I, too, have a 1D that swings faster to the left (away from the winder) than to the right (toward the winder) and I suspect it is a problem with the timing gear mechanism. Some, but not all, of the D models have the ratchet gear speed control at the bottom of the swing-lens shaft, and I understand they tend to behave like that as they wear. I am hesitant to try working on that mechanism since I don't know what I am doing and might damage something. So, I will probably just send it out to Ken Ruth at Photography on Bald Mountain . . . he's the expert on the Panorams.
I have a 4C that I am using to practice Panoram repair, but will probably sell it when I no longer use it for practice, as the 3 1/2" wide film one needs for it comes from those specialty places that sell old discontinued sizes and it's way too expensive for me. I'll stick with Model 1's that use good old cheap 120 film.
You probably have noticed as you read through this thread that there are several of us on here who are sharing our experiences as we work on our Panorams. One area that we haven't really gotten into yet is focus problems with the cameras.
I had one technician tell me that Panorams tend to make soft or fuzzy images because shrinkage of the wood causes the camera to focus beyond infinity. The standard repair for this is to shim the curved film track with narrow tape (something like automotive pin-striping tape). Another possibility is to slit some Teflon tape which will not only shim it, but will help the film to wind easier and keep it from binding and being pulled out of the track and down into the camera.
Glad to have you join us here and would like to hear of your experiences with the Panorams.