I have the old mounts still on the cross member but they are brittle. I could use them and replace later. Something that may help, If you are decent with drawing and dimensioning I could duplicate them myself. Also I would need to know about how hard they are. Material like plastics and rubbers can be gauged on a duromter scale.
If you go to this page
read down a bit and there is a chart of some common items and their durometer. Pick something close and with the dimensions I think I can come up with something that will work.
Even if you just take some pictures I may be able to pull this off.
Thanks for your effort.
Luck is at the intersection of planning and opportunity.