Congrats on your new 5D IV. For all its negatives, it's still a great camera. I'm very pleased with mine and even though I've hade it for almost a year now, I'm still learning how to use it. I kept my 80D, it's my favorite Canon crop sensor body.

Nice photos. I've been to Gettysburg several times and it is a truly unique place. We camped there once but never again, too creepy. If paranormal activity does exist, Gettysburg is one of its major locations.

Cool pics. I've always had a fascination for the old railroad work horses. I guess it's because I'm a rail road baby; both my parents worked for the PRR as did my father's father and his before him.

What on earth are you getting at? Photography is still photography and photographers are still photographers. People can still shoot film if the want, just like back in the day. The beauty of digital is it has expanded photography beyond the bounds dictated by film and the creativity of those who truly understand it. The problem with digital photography is, anyone can go and purchase a D3400 and a few lenses and a speedlites, get cards printed and they are calling themselves professional photographers.

Nice moon, is that the Jupiter II?

Canon makes Canon lenses. There are videos available that show the process from mixing the various ingredients to make the actual glass to the assembly of the finished lens. Canon designs and manufacturers the electronic components in their lenses, components such as focusing motors, micro processors and image stabilization circuitry.
Nikkor lenses are made by Nikon. Unlike Canon, Nikon does farm out some lens manufacturing but all their high end DX, FX and PRO grade Nikkor lenses are built by Nikon.
Early Canon cameras used lenses made by Nikon.
Sigma makes lenses for Sigma cameras and lenses that are compatible with Canon and Nikon bodies and others.
Part of the reason Canon lenses generally focus faster than Sigma or Tamron is the proprietary firmware Canon uses to operate their EOS camera and lens systems.

What kind of telescope does it house?

I too have a Tamron lens that was probably spared because of a sacrificial filter. My Tamron SP 70-200 2.8 was in its neoprene case when it was accidentally dropped on a concrete step. The lens cap popped off and the filter shattered and the outer rim of the filter was bent, but the threads on the lens were still intact, no damage. I believe the filter took the damage the lens would have had the filter not been in place.
I don't use the filters any more, I don't use the neoprene lens cases any more. Each lens now has its own personal foam padded resting place in foam lined metal cases. No more accidental dropping of lenses.

Your repair may not be as extensive as mine was. You may just need the $350 service. Mine needed a lot of parts and I'm sure the AF circuitry isn't cheap.
The way I look at it, I bought the lens second hand many years ago for a very good price. I've been using the lens for many years. It is my favorite lens for general photography.
For $650 Canon cleaned and rebuilt the lens and it is now good as new.
The original cost of the lens plus the cost of rebuilding it was still less than a new one costs.
I'm happy...

Some would also say, who cares.
I agree, it shouldn't have been a problem in the first place but it's not a perfect world and they, Canon, took care of the problem without a problem. Glad you got your lens back, quick and clean.

Do you have about $650 to spare? That's about what it will cost tohave Canon make your 28-300L work as good as new. Price includes shipping to New Jersey.
My 28-300L first began to malfunction when I started using it on my 5D IV. I doubt it has anything to do with the body, just a coincidence, but it worked fine on my other bodies, for a while, then it failed on every body I tried it on.
like yours, mine is also an older one and it served me well for many years. Apparently there is a problem that manifests itself in well used 28-300L lenses. Long story short, Canon replaced the IS mechanism and the AF circuitry and a few other worn out parts in my lens and now it is good as new, complete with a one-year warranty.
I originally took the lens to an independent repair shop but after he took it apart he told me what was wrong and that it is a common problem with that lens and it would cost less to repair if I sent it to Canon. He put it back together, no charge.
I shipped it to Canon repair in New Jersey and after a clerical problem and payment, it was fixed and shipped back in one day.

Canon owners will most likely tell you to buy Canon. Nikon owners will most likely tell you to buy Nikon. Sony owners will most likely tell you to buy Sony. I own all three makes and they all have merit. The best bang for your buck will be factory refurbished cameras or certified used cameras from a reputable dealer or seller. You should be able to get a Canon refurbished 80D with an 18-135 lens for your budget.
Keep in mind, your SX60HS is a super zoom and a lens with as much reach as the SX60HS for a DSLR is very expensive.

It depends on how long you expose the camera to the direct sunlight. Short and I mean very, very short exposure times are ok but anything over a split second can and will burn a hole in the shutter screen or could damage the aperture or burn the low pass filter or image sensor on a digital camera. It is always best to use a solar filter when photographing the sun, not only for the cameras sake but for your eye as well. Even a short exposure to direct sunlight while looking thru the camera viewfinder may and most likely will hurt your eye. A few seconds of exposure may cause permanent damage.
Solar filters should be plentiful and cheap since the 8/21 eclipse.
I personally photograph the sun fairly often so I know what I'm talking about. Don't point your camera at the sun without a solar filter on it.
Have you ever used a magnifying glass to burn something with the sun light? Your lens is a big magnifying glass.

Lumoid has a used 1DX II for $4700. They also have used 6D listed for $950 and a 5D III for $1649.

The article says a $80,000 camera vs a $3000 camera, not a $1600 camera with $1400 in accessories. It is still a $1600 camera, not a $3000 camera. The camera body and the 18-135 lens and a memory card should have cost no more than $1600. He may have bought peripheral accessories for the camera at the same time he bought the camera but they don't count towards the value of the camera. That is like me saying I bought a truck for $50,000 then I had a $500 trailer hitch installed and I got a $14,500 trailer to attach to the hitch. I have a $65,000 truck. No, the truck cost $50,000, the truck, hitch and trailer cost $65,000.
Why would anyone realistically compare a high end professional video camera to a prosumer DSLR anyway?!