Benp
I think at this point I would try cold bluing it to keep it from rusting. If that doesn't look right or if rust becomes a problem I would get the gun hard chrome plated. If the grip frame is aluminum then it can be anodized to match the silver color of the hard chrome plating.
I had a rust problem with my Beretta Model 70S shortly after I got it. Beretta reblued it under warranty but the rust returned. Sent it to Ron Mahovsky of Metalife for his SS Chromium M hard chrome plating. That was well over 30 years ago and the gun still looks as good as the day I got it back from him!
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