Thunder 1-A Bass 1985 version 2 pickups

Hi all, really pleased to see a site exists for these wonderful instruments - and a nice site it is too. I own a black 1-A Bass (1985 version 2) and have been researching it's detailed specs. I can't make out if the pickups are model F675's or F-600B's as information out there seems to be conflicting. What I do know is that it has 2 split coil magnet 'Hard Puncher 1' each with 4 hex key adjustable pole pieces and cross head height adjustment screws - mostly taken from info on this website. Can anyone provide a definitive answer to the pickup model numbers and specs?

Also, any ideas what the dotted fret marker material is? 

Finally, I struggle with the brass bridge and saddles, it was badly tarnished so was heavily cleaned with a wire brush; it polished up lovely for a while but now spots up badly and has to be polished regularly, is there a way to protect them?
Thanks...

A couple coats of clear lacquer  after polishing will sort your brass out,  not sure about the pickups.

Was the brass originally lacquered then? Including the Pot knobs?

Yep.

Great, thanks Sgt. Vimes, I'll get my luthier on the case right away!