Not sure how hard these are to find, but I had one in a similar state and it cleaned up well and functions fine. If you dont like the pitting then I cant help there lol
before and after:
*edit
Hey! I found the button, and the bushing on marco. Bushing is discontinued tho
Ya, I found that this morning too. Oh, I just realized the push-button is still available. I thought it was Discontinued/out of stock as well. Yours cleaned up OK. I'll order a push-button and work on the bushing. Thanks.