RE: Cox cylinder/head tap
I had been thinking of doing some needle valves like the KirnKraft remotes too, but I will likely never find a #2 or 3 x 128tpi tap and button die. I think a 2mm x .25 is pretty good too. If they were a common standard size they are sometimes reasonable, but no one likes to carry stock any more, then they can get a special order price.