I would try some silicone spray in there also.
After blasting mine I had to move the jaws quite a bit to get the abrasive out of them. Even when clean they still had a hitch until I sprayed the silicone in there.
Hopefully that's it and you can avoid removing the door panel and dealing with the linkage.
Scott
'
Camano' 1986 F250 Supercab XLT Lariat 460/C6
'Chanute' 1980 F350 C&C 400/NP 435 - Gin Pole
But there ain't nothin' wrong with the radio