Can't help with the wingnuts, but that sure is a funk-a-delic crank you have! Is it an Ashtabula (one-piece) type with large diameter BB casting? I know Crescent did build some bikes that way. You can fix the RD cable routing with clamp-on cable router (near the BB) and chain-stay cable stop, of course. Silver paint may be covering original cruddy chrome, or might just be a "chrome-alike" look.

Crescent wins the coolest headbadge sweepstakes, in my opinion.