I would just buy a capture plate for you pin box, way easy to remove (allen head bolt) I found my superglide on craigslist for 500.00 it looked brand new
I use grease, tore it apart this winter and found galling on the way tubes ,not too bad but it had to be cleaned up, I painted them and put a good coat of grease on them.
...question about hitch..what do you use to lubricate the hitch rails?
Pullrite recommends a lightweight oil like WD-40 or 3-in-1 for model made after December 2009. I've attached a pdf file of the owner's manual for the Pullrite (4100 series) . Pages 6 - 8 will tell you how to maintain that hitch for best performance.