Just wanted to add - the parts that Bill posted above (WM PN: 19712056 and PK1) fit my Barient 21's and 27's fine.
The pawls and springs in both winches were the same. I also destroyed one of the retaining clips while removing a 21 and the clip that came with part PK1 was just right.
Another tip:
After getting the initial heavy gunk off the parts, i put EVERYTHING in the dishwasher and ran a few cycles on the Pots/Pans setting - it worked wonders on cleaning things up!
-dan