For those of you who want a chrome plated brass CGA 320 nut/nipple/stem, this place has them in stock for $27 shipped if you ask for it to be sent via USPS priority mail (small flat rate).
These come with a filter and are breat quality. I run these on all my chrome plated brass regulators. They are 3" long, so you have plenty of space.
on the left of the screen, (black menu), scroll down till you see:
CGA Parts, Tube Fittings,
Click on this, and it wil bring you to the Smith CGA order page.
Just click on CGA 320 (nut $11) and CGA 320 (nipple $11).
Make sure to note you would like it shipped USPS flate rate small box; otherwise, you'll get it via UPS, which will cost more ($10).
Note: you'll have to pay the $32 upfront, but they will correct this after the order is placed once they switch from UPS shipping to USPS. The total you will pay is $27 ($11nut+$11nipple+$5 shipping).