brand new razors with butterfly doors, only Parker and Wishi come to mind
vintage brings up many more choices with adjustable Gillettes as my top choice
i would call a nice Slim a good one that's not too hard to find
expect tp pay a premium for very nice ones
I have only been back to DE shaving after decades of cartridge shaving - started with a Jagger DB89L. I then added a Merkur 38c. Then I decided I wanted to add a butterfly razor. Thought about a vintage, but could only find them on Ebay and didn't want to gamble right now (and/or do massive amounts of research). So I ordered a Parker 92R over the weekend. Will report back as soon as I receive it and complete my first shave. Will probably start with a Red Personna in it.