Hiya mate,
There is a similar thread about the Diana '45 on the go in this section that it would pay you to have a look at? It may answer some of your queries. I have posted there and wont repeat my long sermon here, but I have rewashered a '50 with ptfe with good results-BUT for a BALANCED view- check out the aforementioned thread?
Good luck with your '50
Handsome rifles aren't they?
Dave