This is going to be tough to replace.
The only place I know of where these might show up is on Ebay.
The usual Colt parts source, Gun Parts Corporation doesn't list them.
You might try contacting Gun Parts, and check with Jack First Gun Parts: http://www.jackfirstgun.com
Probably the best option is to do a better repair of the originals.
You might try cleaning the old glue off, and resetting the bushing with a good epoxy.