727 or 904?

When I ponder on that 904 I think to myself... Is there any way possible any part would fit in the wrong spot? I mean could someone take a 904 and put it 100% back together using all the parts and it be wrong? I mean you can extremely easily air check most your new seals before you even load it in the housing and you can do it then again before you put the vb in? I guess you could do something colossally stupid like put two clutch disc's and two steels together by accident, but no one is that stupid. Non of the servos (3) would fit correctly if each one didn't have all its parts? Am I not living proof that rebuilding a 904 is near foolproof? Not absolutely one special tool required at all. Unless of course a piece of angle iron cut to put in your Vice to take out the clutch pack spring but that's the easiest redneck tool I ever made. Oh yeah I have that whole I need a big massive clean area to do this all on? I found that a 2 foot by 8 foot sheet of plywood with a couple stools under either end was way more room than needed. You have absolutely nothing to lose by opening up a 904. If you don't get all the parts back together and you take it to professional and he can't figure out where things go than you've got the wrong guy definitely. All this comes up when I think about that completely disassembled 904 in my shed again and I think is there a possible way I could bring that all out and put it together wrong? I don't think so.....