Wow grandpa.. I hope that's a typo... A 16K "ton" slider hitch can drag the Queen Mary on land without a trailer. Just teasing your typo, sir.
I don't think the rollers are supposed to rust like that. There is some kind of lubricant that should be used on them periodically.
Maybe you can start here:
http://richsonsrv.com/Parts/tabid/72...5/Default.aspx
or here:
http://local.yahoo.com/info-19021798...uston#overview
to find the parts you need, and ask about how to maintain them to prevent rust in the future.
ON EDIT: I think I found what you are looking for. try this link:
http://www.huskytow.com/Literature.aspx
Then open the p77 pdf file and scroll down and I hope this is your hitch and shows the parts including the rollers
Good luck to you. Let us know how you do!