Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
I just picked one up at NAPA the other day. it's a THM 358-180 cost me $32.65. The seal is a 4662 and cost $3.25.
I was told not to change over to 100% co2 because I would need a second different regulator then the one I have.Go with co2 it's cheap but do not run 100% argon it's to hot for steel and the carbon needs the co2 to cool the tip and burn properly. We use 100% argon for aluminum only.