I recently obtained a Pratt Burnerd 6" 3 Jaw set-rite (4 adjusting screws at 90 deg) chuck Catalgoue No. 1219-00360. It is new old stock and was very gummed up with anti rust paper remains. It has apparently sat on the shelf since the early 1980's.
I have taken the jaws out and cleaned it as best I can. I understand that these are made to a tight tolerance but it is still very stiff. There is a grease nipple. I expect any grease inside will be congealed. I want to open it up and clean it and re-grease.
Does anyone have any advice or a copy of a maintenance sheet? Picture of rear inserted below and there is a front and side in my album.

Thanks,
Steve