Evolution of the Silca Pista Pump

[Spaghetti Legs]

I have a Silca Pista that I bought NOS off ebay 2 or 3 years ago. I think it's probably the last version before the hiatus and recent triumphant return. It has an aluminum body and triangular base. The hose comes out at an angle from the base. Anyway the check valve failed a couple of days ago (inner valve I believe in Silca terminology) manifested in the handle majestically rising after pumping air into the tire. I was kind of surprised as I've read the part is supposed to last 20-25 years.

When I took the pump apart, the manifold is also made of aluminum as is the bolt securing the check valve. My impression is that on the classic Pista, this part is all brass. I was hoping to clean things out, clean up the o-ring and put back together. The threads on the bolt, though, are very worn and the bolt, now won't tighten down securely. I've ordered a new check valve assembly with a brass bolt from nonstopciclismo. They advertise it as old stock from the Silca Italy days. Silca website just has the needle valve and spring without the bolt.

My point of all this I suppose is satisfying my curiosity about the aluminum content of the pump. Has anyone taken apart their new Pista pumps? I know the body is steel now, but are the innards all brass or aluminum? I kind of wonder if when Silca was bought out, was my version of the pump the initial, maybe not as reliable iteration?