G’day Pat, welcome to the forum. IMO one good option would be to post pics of a rifle you’re looking to buy on here and one of the aficionados on here will hopefully chime in on how original it looks!

BTW, I know of an original Type B in 6.5x58 Portuguese that I think is sort of for sale - he’s an old time Mauser gunsmith and dealer, straight as they come but won’t get much digital action out of him. I think it’s got silver inlay, not sure about scope mounts. I don’t have any pictures and old mate’s in the dark ages so getting digital pics would be slow. I’m guessing he wants about $2500 for it but I never enquires too hard. It’s in NSW. PM if you want his details or I can call him to get more info...