Repairing/replacing Arco Convectors

Moved into a new house. Had a freeze up on one zone before we arrived and had to replace some convectors and fittings.

I’m looking for additional convectors for spares and would appreciate anyone who could help save the ones we have.

We’ve repaired two so far where the endcap had a hole or a crack. Replacing cartridges seems to be harder to do. Is there a tool to rejoin the cartridges, like cast iron baseboard or another safe way to join sections back together?

Please contact me anytime if you have arco sections, parts or governale convectors to sell we intend to stay in this home a long time and want spares.

Thanks