Alright everyone, I was able to identify the found item that the top right canister was based on. I say "based on," because the item itself weighs a TON, and there's now way they used a real one on the packs. For mine, I'm eventually going to do a resin cast of the one I purchased:
http://i.ebayimg.com/04/!B6(H4CgCWk~$(KGrHqYOKjIEyPC3INo+BM)HfbDv-w~~_12.JPG
It's a
Teledyne Taber Pressure Transducer/Transmitter, and I strongly believe it to be based on the type 176 model.
Also, I added a few missing labels to my pack before our outing at this year's D23 Expo --
here's a gallery from that event!