I do not know where else the vin may be. In NC, they never check that. I would say to talk to someone at the DMV, tell them why, show them your proper paperwork for your truck, a bill of sale for the other cab, have them verify them, then get them to make you a new vin tag for the new cab. I know Cali is different, and a PITA so I hear. I'm shure you aren't the first to need to do this.
Lifting??? that is what friends and beer are for. have everything unbolted, then have a truck party. Things get done quickly that way. Get it all swapped and bolted down, eat some burgers, then you can make the connections later.
Don't you have an old swingset for an a frame? Build one out of leftover lumber, jack one side, crib it , then the other until you can slide a board through the cab to rest on the a frame, roll the truck out. Drop the cab, then do the same for the new cab and do the same in reverse.
What happened to that Yankee farmer enginuity????