Here’s a link to the Exakta camera manuals available as PDFs on the Butkus site. There is a listing for “Exakta VXIIb,” which according to Camerapedia, is what the Varex IIb was sold as in the U.S. There’s also a listing right above it for the “Varex IIa” for what that may be worth. (Not sure if there are any significant differences between the IIa and IIb models.)

Here’s what I use with my Linhof Super Technika IV 6x9.

--Gitzo GM3860C
--Sunwayfoto Leveling Base DYH-66 (actually a type of ball head)
--Desmond Arca Swiss clamp DLVC-50

Not sure how much it weighs exactly (couple of pounds maybe). Measures 19½” from clamp to tip when fully collapsed.

To quote DPReview: “In the … office we'd call it a 'stunt' lens: one which you'd use for very specific purposes and effects. It's most certainly not for every image, or indeed for every photographer; in fact we're pretty sure that the majority simply won't see the point. But some will exploit its characteristics to produce compelling images that really couldn't be achieved any other way.”

… and there is [video] in my Leica M (typ 240). Go figure. :)

Not true. As the OP mentions, Leica (in 2005) came out with a true digital back -- the Digital-Modul-R or “DMR” -- that can be fitted to the their R8 and R9 135 film SLRs. It was only in production for a couple of years but they can still be found on eBay from time to time.

Okay, I don’t have a dog in this race -- don’t use Nikons or large heavy lenses, or the types of straps being discussed, for that matter -- but the mechanical failures mentioned by the OP make me suspect that he just might have one of the bogus MB-Dll grips for sale out there; and that is the real problem in this case, not the alleged “inherent danger” of using the tripod socket as a point of attachment for a strap per se.

Just my 2¢ anyway :)

Your guess is correct -- “1:4” is not the same as “f/1.4” (which would be indicated on a lens as “1:1.4”) -- and yes they would be very different lenses.

However, since you also mention not wanting to throw away money needlessly, it seems to me that, regardless of the seller's screw-up, the real question is whether or not this 12-24mm is best suited to your needs as you describe them. I can’t say, but I’m sure there are others here who can give you advice in that regard.

Page 252 of the GX200 User Manual states:

I did a search on Rangefinderforum and couldn’t find anything addressing either your particular “film fragment” problem or general disassembly of the IIb, for that matter. (Didn’t check APUG.)

I also checked Rick Oleson’s repair pages and while he doesn’t have any info on your Canon, he does have some hand drawn illustrations relating to the Leica III’s -- you can find them HERE. Perhaps they might be of some help.

On this topic, here’s a link to the Camera Manual Library maintained by Mike Butkus. This has been an absolutely invaluable source of manuals for all sorts of both common and obscure photography gear -- cameras, light meters, flash units, and a bunch more -- for years. (And they are all free, although donations are appreciated.)

Just an FYI, there are two variants of this particular lens, a Takumar-A and a Takumar-F, and both are K-Mount. (There is no M42 version.)

Perhaps the OP will sell his. As agillot indicates, K-Mount to Nikon adapters are available but I’ve got the sneaking suspicion that a proper one, i.e. "with glass," may cost more than the lens itself is actually worth on the open market. :)

Although written for a US audience, this lifehacker article might provide some guidance in your situation as well.

Don’t know if you’ve already done this but out of curiosity I just did a quick search: Pentax ist DL mode selection problem, on the PentaxForums cite -- results are www.pentaxforums.com%2Fsearch%2F%3Fq%3DPentax%2Bisd%2BDL%2Bmode%2Bselection%2Bproblem%26cx%3Dpartner-pub-8894193256862854%253A3882095764%26cof%3DFORID%253A9%26ie%3DUTF-8" rel="nofollow" target="_blank"> HERE. Might be something helpful on the list of hits. :)

If you click on "1957" in my post above you'll see a really neat red one. :)

Don’t know if this adds anything; but judging from your post, I guess the RRS has a suitable screw hole like the Sunwayfoto L-bracket pictured below, so, yeah, it’s possible to attach the “Camera Hub” (red arrow) off center and this, in turn, allows you to slide the plate into the Arca clamp on the tripod head.

With this arrangement, however, the camera is going to hang askew when you fasten it to the vest (second photo below). If that is a problem, you could use a short strap of some sort, with one end attached to the camera lug and the other to the tether ring provided on the vest, to bring it back to a vertical hanging position.