Moxey was evidently sued for patent infringenement and put out of business by Thudbuster.
There may be a source for Moxey NOS parts, perhaps ebay.
You might be able to "Gerry Rig" something using elastomers from other sources. Birdy bikes for example uses a similar material on their rear suspension, also Moulton. I have seen heavy duty elastomers sold at HVAC places for use in vibration isolation, if you show up when it is not crowded with HVAC techs they might be willing spend some time on your problem. Anything with a powerful motor would also have elastomers to reduce vibrations. Try searching on vibration isolation.
Probably cheaper sell yours and buy a used thudbuster. WHen patent protection is lost maybe Moxey will be back.
2000 Montague CX, I do not recommend it, but still ride it.
Strida 3, I recommend it for rides < 10mi wo steep hills.
2006 Rowbike 720 Sport, I recommend it as an exercise bike.
1996 Birdy, Recommend.
Wieleder CARiBIKE (folding), decent frame.