Take digital pictures of everything, pick one or two of each when posting for sale. Research prices of everything. Most of us like KEH, but I know from my own experience, they have several people answering the phone with different personalities. Make an assessment of the 'grade' of each item. If it seems 'like new' or only modest use / wear, use the KEH website to find their current selling price of an EX-rated version of the same equipment. Then, set the selling price at 75% of the KEH price. Personally, I don't care about the original box, but if you really have access to the original packaging, this is both a curse and a blessing. It might fetch a higher price, but shipping in-the-box is likely more expensive than the cheapest shipping option of the 2-day prepaid USPS priority mail boxes.

If you want to sell here at UHH, you can create a single posting and just attach a spreadsheet of all the items. Suggested columns would be:

Item count (1,2,3,etc) for reference purposes.
Item description, try to be as accurate as possible such as Canon EF 50mm f/1.8 II
Box included: Y / N
Price: pick a price that includes your assumed cost for box and shipping, state the price includes shipping included to US addresses
Pictures Available: Y / N (indicate pictures can be forwarded upon request)
Status: Available / Sold

In the UHH section, you can create a single post and continue to edit / re-edit as the sale progresses. If you use the spreadsheet idea, you can just edit and re-attach the updates as each sale is completed. If you don't like the spreadsheet, you can just create a series of rows with the consistent attributes for each item / column mentioned above.

The work above would be needed for any sale vehicle, ebay, KEH, MPB, etc. That is, you need an inventory of the equipment, probably 1 or more pictures, an assessed grading, and a desired sales price.

I prefer the USPS boxes since they come in standard sizes at fixed prices. Items like a lens or a flash, even a small(er) camera, can be wrapped in bubble wrap and fit into a medium box that ships for $20 to any address in the US in 2-business days. You just have to bring you own tape and Sharpie to seal the box and address, buying additional insurance, if needed above $50. When you start shipping original boxes, now you're at the mercy of FedEx or UPS and the price goes up substantially.

For lenses, take a picture of the front and / or side that shows the brand, focal length and aperture. Don't worry about serial numbers for any of the equipment, just the brand and model information.

I have offered and am organizing an entire room/ofc of an friend who passed last year. His career was teaching photography. Needless to say this is a major task. I found this out yesterday when I spent 1/2 day starting to sort through stuff and his wife told me he never threw away anything. Fortunately that included every box his cameras and lenses came in.
I called KEH and spoke to a women in the resale buying dept. I wasn’t happy at all with her help and made an excuse to get off the phone. Very different from 6 mos ago when I called about this same thing.
This being said I am open to any and all suggestions everyone may have. I offered to help as my friends wife of 54yrs is in her 80’s and hasn’t a clue about all his gear.
I appreciate your advice.

I bought and sold a LOT of photo gear on ebay over about 20 years, including all the bodies, lenses, fittings and trinkets when I switched from film to digital 15+ years ago. This included Leica, Hasselblad, Rollei, Minox and Nikon film equipment. AND a Graflex flash handle. (Sure wish I'd kept those Leica rangefinder lenses for another decade or so.)

But after an experience selling some Nikon digital equipment when I switched to Micro 4/3 format a few years ago I will NEVER sell on ebay again.

An ebay buyer now has an absolute right to return a purchase by just checking a box "does not meet description." YOU pay the return postage, and you have to refund the full purchase price plus shipping that the buyer paid. (Ebay does refund your transaction fees - how nice of them.) You have X days after being notified of the buyer's return decision to authorize the return shipping or ebay does it for you and charges your payment method. Same for returning the purchase price - ebay gets notified of delivery of the package to you and you have X days to authorize the refund or ebay does it for you. IOW, the buyer gets to play with the equipment at no cost during the decision period. You cannot override this buyer right by saying "no returns" in the listing.

I saw NO provision for being able to dispute the does-not-meet-description checkmark - even if what you sold was new in a sealed box they can check the box and you have to pay return shipping and refund the price. And of course you no longer have a new-in-sealed-box item to sell. Tough. (The item I sold that was returned for not fitting the description was a barely used, recent production Nikon FX 50mm f/1.4 lens, which the buyer said had an aperture ring that wouldn't turn - the ring was fixed in the Auto position by the little lock on the lens, and turned and worked like new when unlocked, but I had to pay return postage and refund the purchase price.)

I also saw NO way to adjust for damage done by the buyer or in shipping, or for pieces missing from the returned package - if the buyer ships a box and you get it you have to refund the full price, regardless of what's in it. Maybe there's a way to adjust for this kind of subterfuge, but if so I didn't see it in the one - and final - experience I had selling on ebay.

FWIW.