There really isn't a stub at all. If anything, the wire end may be slightly recessed in the glass. It's hard to see, much less reach.
I tried soldering single copper strands to the existing leads, just to see how hard it will be to attach guide wires. I scraped the old leads shiny and tried to tin them beforehand, but had a heck of a time getting solder to stick at all.
Is there something else I can do to improve adhesion? If not, I see no chance that I could solder a strand to that stub. Maybe cleaning the stub shiny and fastening a lead with epoxy is the best I can do.
I'll need to redo the test strands, in any case. They're only about an inch long. I realized too late that it'll be easier if they're several inches long, so you can bend and insert each guide wire separately, rather than try to line them up and insert all at once.
Phil Nelson