I bought a piece of Medium Hard SBR rubber ... 1" thick, by 6" x 12" for about $14 from McMaster .... appears to be the same thing used for radiator mounts, body mounts, probably everything except suspension bushings.
Cuts with a band saw, smooths with a 1" belt sander, grinds with a dremel and a course sanding drum, trims with a razor blade. Yes it's tedious, but I have some spare time and for unobtanium, or expensive stuff ...ehhh ... not so bad to make your own if you can.
Yes ... evidently everything that fits a 69 will fit a 68 ... whether it does or not
I realize 68 was a first year of a new model, and a bit of a red headed step child ... but a lot of places are just plain misleading customers to make a few extra bucks on a repop.