David ,

I think its not a big problem unless if you feel the engraved metal with your fingers. I think if metal feels like a needle , you can smoooth it. Best way is to use a 1200 grade filing paper which will smooth the engraved area. You can find it at internet or a department store. Minolta SRT is an excellent and looks like a army piece and lenses are legendary. 1200 grade paper is so fine ,it shines your finger nails.