I recently up-sized my acetylene cylinder from a 40cf (B) to a 60cf
(wq)tank.
When I tried to attach the spud end of the regulator to the new
cylinder, the regulator gauge hits the rim of the cylinder so i
couldn't tighten the regulator spud nut. I stopped by the hardware
store (the welding store was closed by now) and (of course) they didn't
have any regulator parts. But they did have brass fittings. I removed
the spud from the regulator and replaced it with a 1.5" double ended
brass fitting, then a brass coupler, then the original spud (to
lengthen the spud). I used teflon tape on all the fittings. It works
fine with no leaks. The regulator is brass so i figured brass fittings
are adequate.(i know copper is not)
Does anyone have any thoughts or safety concerns with this set up?

thanks,
walt