Thanks, all, for your helpful advice. I'm not sure why I even asked about sanding sealer - guess I was just wondering if anything other than filling (ding repair) and sanding was required (or helpful) prior to covering. I definitely plan to practice on some scraps before I start in on the model.
I keep hearing about how important it is to cover "everything" - that is, to fuel proof the wood. Guess that's why I thought the sanding sealer (or something similar) might be a good consideration. How important is the fuel-proofing anyway? It seems that one way to correct for bubbles is to pin-***** then. Doesn't that break the integrity of the covering? Hinge cut-outs also seem like an "uncovered" area. And what about the aft end of the inside of the fuselage? It's pretty hard to do much of anything with it now that the top and bottom panels have been added.
Sorry for all of these questions - You veterans are probably have a good chuckle or two.
BTW, I attended my first swap meet this past weekend, and I have to say, the covering jobs I saw there were pretty wrinkly for the most part. Guess that attests to how hard covering can be, and why one (especially a beginner) should not expect perfection. My nature, however, kinda makes me want to strive for "a perfect job".