"Pinkie", as John/boreas named it/him in 2018, was a big mystery when he/it showed up. Naturally I had to have my own example. In 2023, hucklecat discovered the similar Astatic-packaged S999VE ("Purplie"?). If you have an S888TE "Whitie", I'd be gratitudinal if you'd post a photo of it. I do like your idea that it was an OEM version for repackagers/resellers like Pfanstiehl and Astatic. Found a photo in my archive of an S888E "Greenie"! Not only that, but an early height shift in 888/P/PE mounting ears.
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I did discover that one of my 4236-ZDEs (Walco?) looks much like yours. In any case, if output is deemed insufficient (I don't recall noticing this or testing it, but will test), a craft knife should slice right through the problem.
The 999 VE/X and 1000 ZE/X bodies have this slight difference compared to the models that came after, but both seem to find their origin in the 1000 ZE of 1970. I wish I had better photos, but here's what I have. Left to right: ZE, VE/X and ZE/X, all with what I call the Cartoon Mousehole opening into the body in lieu of a simple round hole.
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Of these, the only body I own is the 1000 ZE/X, and of course it too isn't here. I would not be surprised to find a photo of the ZE stylus that has the tab. Why the VE/X stylus lacks it, I have no guesses, likewise for the fact that the ZE/X gets Pfanstiehl's 236 prefix all to itself, when it's clearly closely related to the VE/X. Whew!