First-version 6-in-line set with metal bent-tab ends.
Here's why they're called 'tab-ends'. The ends are closed by metal tabs on the casings bent 90 degrees to form the ends. It didn't take Danelectro very long to realize that these ends could be manufactured much more efficiently by cutting the machined casing stock flat on the tuner set ends and inserting a nylon end cap when the tuners are assembled; Easy to make either 6-in-line or 3 + 3 sets that way and reduce the amount of casing stock to boot. Except for the tab-ends these tuners are identical to the nylon end-cap versions.
Skate key tuners clean up well, like the ones below that were typically corroded but cleaned right up using a Dremel wire wheel and 'PB Blaster' catalytic oil followed by a Dremel buffing wheel.
Using a well-worn 3M scrub pad with 'PB Blaster' will also clean up corrosion while leaving whatever amount of vintage patina a person might desire, like the tuners below were (when removed from that guitar of course).
