The new scans are up! (THANKS to Rhgbristol!)
Membership at Vinyl Engine (free) required to download. The pages with the download links are:
1981 catalogue
GT255ap-GT355ap instructions
I have a Garrard DD450 and it performs well, indeed. When I acquired it, my DD450 suffered from the same problem that
afflicts many in the Advanced Design Group (wherein Garrard moved the operating controls to the front): a broken cueing
linkage. I haven't reached those models yet in the Deck Identification series but soon will, and will explain the problem
at that time. My DD450 also has an S-shaped arm. Garrard changed the tonearm midway in DD450 production from an
S-shaped arm to a straight arm. The catalog that is downloadable above shows the straight-arm version. The attached
photo shows one with the S-shaped arm.