umm there's 2 kinds of the stabs with screws, the other one looks like this:
I saw those in one of your OTD articles. Very nice. Do you have a photo of the bottom of the stems?
There are two 'variants' I know of, aside from the one you mentioned.
One is like I posted in the OP. Note the shape of the bottom of the stem insert.. I have some of these from a Nixdorf softtouch PCB.
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The other kind looks the same, but has regular, modern inserts. I have some of these from a Skidata board.
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I'm curious to see the stems of the style you posted.