Bob Long 2k2 Cupseal Material

I'm looking at options going forward for my 2k2's. I'm exploring options for cupseal replacements/general poppet setups. I was wondering if anyone knew the following:

1. Were the 2k2 cupseals nylon, neoprene, ptfe/teflon, or something else?

2. Were the Black Magic seals nylon, neoprene, ptfe/teflon, or something else?

3. Has anybody tried using nylon, neoprene, pfte/teflon, or something else flat washers in their 2k2 setup for a cupseal replacement? What were the results?

4. Does anyone still sell Empire (ie. Gen 2.5) full setups? Ie. stem and poppet?

5. Is the easiest thing just to get an Empire poppet shaft stem, Gen 5 LP poppet, tap it, and use that with the 2k2 poppet spring? Or was another spring recommended?

I realize PBGateway and Oring Monkey still have 2k2 cupseals--I'm just trying to plan for when they run out of them.

Thanks.

The white ones are teflon.