DeArmond did not make the Mickey Mouse pickups. Guild sourced from multiple pickup companies around the east coast at that time, and from what I've seen, a catalogue from that era states they are "frequency tested" pickups, which to me means cheap, which is why they installed them in their student model guitars like the T100 and M-65 Freshman. Dont get me wrong, i love my 65' T100-D, and you will love yours as well. They really overdeliver for the price, especially considering they are vintage. The mickey mouse pickups are actually very woody and can produce some nice hollow body jazz and rockabilly sounds, so they are unique in a way. The Franz pickups in my experience are slightly more aggressive with more attack, much more P-90 like.
As for the bridge, if its in the right position for the intonation to be accurate (as accurate as a compensated floating wood bridge can be that is), i wouldn't mess with it. If there are intonation issues, you may be better finding a cheap metal tune-o-matic bridge to place on the wooden base and adjust from there. The finish on these guitars is very thin, and although Grot's is very clean, most of them are chipped to hell. Id worry that pulling the bridge off would take a chunk of finish with it, and mind you its painted so it would leave a natural maple wood color exposed which would stand out. And a glue remover would smudge or ruin the thin veneer, unless you have somebody who is extremely experienced with it. Lets hope it is glued in the exact right place
, it will certainly make changing the strings easier! A great score either way!
Mine is from 65', notice the chipping, the less dramatic sunburst, and the all plastic pickup casings. Grot's and most likely yours look better IMO. I also attached photos of the underbelly of the pickups, which are not embossed or identified in any way by any specific company - soooo yea, cheap.