Does anyone out there know definitively what the masts for Mercury models were made of?

I am in the process of replacing the broken masts on 3 models. I have managed to remove the stubs from two of them. The stubs look identical to hardened steel pins used for picture hanging, complete for colour, point and brittleness. Were these as original or previous repairs?

Unfortunately the third appears to have a blob of solder on the underside holding it in place. Time for more experimentation!

Ian