If you broke those two rectangle shaped objects, you will have to find replacements. That can be difficult, as most hardware manufacturers only sell replacement keyboards, but individual replacement key parts.
If you take your laptop to a dedicated laptop repair shop, they may have spare keyboard parts from other deal Compaq's.
Of course, those two little rectangular pieces (I wish I knew their names!) can be
extremely difficult to fit back together. They may not be broken at all. If it were me, I would take another key apart to see how they are supposed to fit together. I'd probably pick a key that I wouldn't miss too much.
I can't visualize what you could have moved on the motherboard, and you certainly shouldn't be able to
move the motherboard with compressed air. If it were me, I would be tempted to take the notebook apart just to reseat the motherboard and check for damage.
Or, you might want to take it to someone local to you who can physically examine the laptop and give you a good estimate.
You're in Edmonton, right? A quick web search found:
Laptop Medic
10624 105 Ave Nw
Edmonton, Alberta
T5H 0L2
Phone: (780) 493-8105
Fax: (780) 493-8106