Quite a conundrum you have! I have no definitive answer, and while I have collected lower denomination AC chips, I've never done $25s, $100s and up.

Here's my thoughts (Sorry, in advance ... it's wordy.)

I'm assuming that the disassembled one in your pics is counterfeit, not one of the "temporary" rack (Black's Showboat 100-b) that Paulson provided to Showboat AC for a short period while they were re-racking to Black's Showboat 100-c (with the hologram). Correct?

Note: I know you're aware of this, but for others, to understand the unique nature of the GENUINE version of Black's Showboat 100-b, readers should see note on the ChipGuide here: http://chipguide.themogh.org/cg_chip_search.php?ccg=044022.

A place to start is with the original Showboat $100 (Black's Showboat 100). It's an expensive one now, but you have one, or can borrow one, I suggest you X-ray it ON ITS EDGE, and also get a GENUINE version of this chip (Black's Showboat 100-b). If the "100" chip has a standard thickness metal disk (about 1/8 inch?), then we know the practice was to add weight, plus it is an anti-counterfeit signal too. If the "100" has only a paper thin disk, like the one in your pics, then its use is as a hidden anti-counterfeit signal only. (And if NO disk at all in the "100", then Paulson inserted the thin disk in the GENUINE 100-b's to foil counterfeiters that might use other solid black chip bodies (from other casinos, etc.) in manufacturing counterfeit chips, with the assumption that an x-rayed disk must be a standard size&shaped weight.

Paulson wouldn't need a full size metal disk, as they're starting with a solid black blank without most of the center clay material removed. Maybe the weight of the 100-b's is not exactly the same as a 100, but the chips were only going to be used for a short time (4-6 weeks).

(A complicated senario to follow, I know! Basically, by comparing (weight; x-ray on edge) among Showboat-100's, Genuine Showboat-100b's, and Fake Showboat-100b's -- and even Showboat-100c's, though the first use of holograms on the 100c's changes the need for internal weights/wafers as an anti-counterfeit device -- you may be able to establish a pattern... with the objective of being able to NON-DESTRUCTIVELY discern between genuine and fake versions of the 100b's (even though doing an X-ray is required. That's where getting friendly with your dentist (like "Doc" Myers used to do) comes in.

Undoubtedly, that quirky 100-b chip, with its hand-painted inserts, and its genuine vs. fake versions is very unusual. A good "talking about" chip for sure!

Thanks for showing it.