Regarding the gas tank saddle on my 102, I remember vaguely some type of padding between the saddle and the gas tank, but I can't find any remnants around the garage. I think it was some type of rubberized fabric, but I'm not sure. It's a small detail, but if there's supposed to be something there, I'll make new ones out of some of that polyester reinforced neoprene I mentioned earlier.
Matt,
I'd use the old cable housing for a guide if it is available, if in doubt cut it a little longer than you think you'll need, if you make a mistake its much better than cutting it too short. I tend to hand fit these kind of cables, I take the inner wire out, then route the housing the way it should be routed and trim it a bit at a time until it forms a nice smooth arc, without bunching up or sticking out some place it shouldn't. Be sure to leave a little bit of slack to do adjustments once everything's in place. Once the housing is in, I'll cut the inner wire, again leaving it a couple of inches longer than I think it should be, then only cutting it to final length after doing a trial fit.