Back in the middle '70s, the Mopar jobber I got some things from had some catalogs they were getting rid of, so I asked if I could have them. There were parts for all brands, but I wanted them for the Chrysler listings more than anything else. Plus to try and make some sense of the Chrysler parts listings for the turn signal switch for my DH43N0DE (tilt wheel w/cornering lights), which it did. That was circa 1976 or so.
As for the hard parts, you can probably find them in the Standard Parts section of the normal Chrysler parts catalog. Nuts, bolts, plugs, bulbs, etc.
The belts should have the size (length and width) stamped on them, which might then be crossed into Gates numbers and applications, I suspect. There should be a "Buyers Guide" in the back of the Gates catalog, plus listings by length and width combinations, usually. Might need a paper catalog for these things rather than a current online catalog.
Hope this might help . . .
CBODY67