I'm with the OP on this. I like to have the manuals to the rig -- just look how many questions on a place like this or at farcebook could be avoided with the manuals at hand. As an example: winterizing instructions for that specific rig.
I agree that it is more important to find the manuals for the appliances and attached equipment, though -- most of which can be found online.
Now, finding manuals for a 20 year old rig -- that's another matter.