First, specify which "D7" you have. There are all these: Mariner D7, Speed D7, Vybe D7... and maybe more!
Second, images would help. You need 10 posts, but you can post a ("camouflaged") link to images elsewhere in the meantime.
There are some bike shops in Chicago that sell and service Dahons. Contact one of them.
EDIT: I have two Dahons, and neither one has any sort of rubber shim in the handlepost mechanism. Be careful "jury-rigging" this critical control assembly. Dahon's are well-designed bikes, and if things don't seem to fit there is a good reason.
Last edited by sweeks; 06-20-21 at 10:03 AM.