[morzh]

I bought HolsterSmith setter and also the eylets by them.

I think even #8-9 length would do, but then when they are being put together, there is a lot of play initially, and the longer one (#8-12) from the kit was easier to work with as it has more protrusion, and, when flared, goes exactly where needed.
The Philco rivet problem was, the flared part was so small, and the rivet itself so thin, it readily separated into a thin ring and the rest of it, when I just touched the bulb. The second socket lasted a bit longer, but also separated without a major effort on my part.