Stainless CGA320 nipple (>2"): $24
Stainless CGA320 nut: $24
Stainless in-port filter: $13
All plus shipping.
Pm me for the website.
COntact customer support at Matheson and ask them for the proper part number. Stainless is more expensive than brass generally speaking. But a stainless gauge (new) will run you about $50. You can try to find a used one, but good luck...these stainless units are harder to find. They are not like a model 8.
Sometimes the replacement gauges will not match exactly. If you're a stickler like I am, you can replace both gauges at the same time and save the good gauge for the next vintage regulator you pick up.
Again, PM me if you need any help.