ABAC compressor fault

Hi I am desperately looking for help. I acquired an ABAC B2800 compressor for free a few years ago and after changing crank bearings has been running well. Turned it on the other day and left it to build pressure but on my return there was little pressure and the motor had gone out on thermal. Motor has been checked and ok. Took the top off the head and the valve plate parted and the flapper plates scattered around the floor. I need to know the positions these need to be in. Cant find any drawings on the net to help. Also need to diagnose original problem.