Duo-Sonic II wiring diagram
Exploded-view line drawing of a Duo-Sonic II
Selected parts list
The official Fender parts lists for the Musicmaster (not called "Musicmaster II") and the Duo-Sonic II depict early models on the front, probably from '64. It is difficult to see in the scans, but in both cover photos the bridge saddles appear to be made of unthreaded rod stock (like the very first MM/DS's in '56) rather than the threaded stock used thereafter. (The saddles look similar to the ones shown on the Musicmaster II on page 230 of Richard Smith's book, "Fender: the sound heard 'round the world".) However, the exploded view drawings of the Duo-Sonic II and Musicmaster both depicted F-tuners, which were introduced in '66 (although some necks with a late-'65 date stamp had them). Combined with the absence of the name "CBS" (the only credit is "Fender Musical Instrument, Santa Ana, CA," their sales office address), the parts lists were probably printed no earlier than mid-'66.
A wiring diagram was also included with the Duo-Sonic II parts list (the same diagram can be used for a Mustang). The Musicmaster's diagram was similar, with the black lead from the neck pickup grounded to the volume pot's outer shell. (Seymour Duncan has (had) a Duo-Sonic wiring diagram online, but it must have gotten lost when they redesigned their website. In the meantime, a copy of their wiring diagram is online here.)
Selected parts list (screws/fasteners used)
Replacing rusted-out screws and other fasteners can be the most maddening part of any restoration project. The information in the tables below was taken from the parts lists mentioned above. "Drawing no." refers to numbers in the exploded view line drawing of a Duo-Sonic II rather than part number. I'm pretty sure that all MMs made from then on also used the same size screws, etc., but I cannot guarantee its accuracy for the Bronco-esque Musicmasters of the late '70s. Similarly, I know most of this information to be correct from prior experience, but if the parts lists contained errors, I could have unknowingly transcribed the errors here. (I managed to catch at least one error: the "names" of each string, listed with their gauge, were "E A G B A E", low to high.)
Screws used for: screw type head diameter length quantity drawing no. pickguard, control plate sheet metal oval #4-40 1/2" 15 9,18 pickup height machine round #6-32 5/8" 4 13 slider switch machine oval #4-40 1/4" 4 12 bridge plate sheet metal oval #5 1" 7 28 bridge (length adj.) machine round #4-40 1 1/4" 3 34 neck plate sheet metal oval #8 1 3/4" 4 35 strap buttons wood oval #6-32 1" 2 49 tuning keys, string guide wood round #3 3/8" 13 40,46 All screws have Phillips sockets and are nickel plated steel Other parts: used for descr. diameter length quantity drawing no. set screw, .050 Allen saddle height oval point #4-40 5/16" 2 32 set screw, .050 Allen saddle height oval point #4-40 3/8" 4 33 compression spring bridge 15 1/2 coils - 1 1/16" F.L. 3 30 trim washer output jack flat 3/8" - 1 24 lock washer pots, jack internal tooth 3/8" - 3 25 hex nut pots, jack 32 thread 3/8" - 3 23 String gauges (low to high): 0.052 0.044 0.034 0.026 0.016 0.012