I looked and didn't find a lot of threads on door check repairs. This is one of those little irritants that drives you crazy over time (ie door won't hold in the open position).
On the 67-72 the door check is built into the upper hinge. The biggest issue is getting the roll pin out to free the part. on my drivers side the previous owner had put a long screw to replace the pin, so it was easy to get out. On the passenger side I got a 12" long 3/16" drill bit after having no luck pounding it out.
Here are some pics and procedure for those who want to do it:
1) Remove interior door panel
2) Drive out roll pin
3) Remove check
4) Remove and replace check friction pads
5) Reinstall check (I used a piece of paper towel to hold the 2 pieces separated until I slid the check between them.
6) It was extremely tight so I gave it a good dose of lube. Really holds nice.
https://www.lowes.com/pd/DEWALT-3-16...B&gclsrc=aw.ds