Anyone got an HP Paintjet printer?

This is going to seem like an odd question, but here goes... I've borrowed a Paintjet (colour inkjet) printer from HPCC (as you probably all know I am somewhat invovled with that club) with the idea of taking it apart, figuring out how it works, etc. Yes, the club do know I do that sort of thing :-) So far, so good. I've figured it out, made notes, and put it back together. Problem is, I can't get it right... Here's the problem. There's what I'd call a 'pressure bail' that holds the paper against the platten. It carries a transparent plastic window. And that window seems very loose. So loose, in fact that it rubs on the ink cartridges when you move the carriage. And when the carriage moves to the far right (parking position), the window drops so far that it jams the carriage, which then can't move back to the left. The problem is compounded by the fact that I don't know that it was correct before I took it apart. I do know I've got no bits left over. I also didn't dismantle that part of the printer (I did remove the logic board and mechanism from the case, I did dismantle the mechanism far enough to remove the carriage and motors). I can't see any obvious places where something (like a spring) should go, but equally the finish on the tabs of the window (I did remove that _after_ I discovered the problem in an attempt to find it) doesn't look as good as I'd expect from old HP. Maybe some tabs have broken off. So my questions are (if you have a Paintjet, original version) Look at the windw in front of the platten on top of the machine. Does it seem to sag at the front edge, or is it forced up against the inside of the case. If you can remove the cover (I can tell you how to do this, it's easy and doesn't need tools), I'd like to know just what supports the window. Are there any springs or spring wires/leaves on the front of the pressure bail? Are there any 'extensions' to the tabs on the window at the front of the bail? If I know thrre's something missing/broken I can have a go at making/kludging it. -tony