!/200 DKM Tsingtau

Phil "Bondo" Brandt was an excellent modeler out of Austin Texas.    Phil preferred "difficult" kits and Bondo was his weapon of choice in his projects.    Phil's was a fixture on Hyperscale.    Phil passed a couple of years ago while on vacation in Europe,

Also a good choice. Wasn't there a member named Bondo?

I think I would go with Bondo auto body filler

Its available at Auto supply shops (Pep Boys, Auto Zone, O'Reillys)  and at WalMart,  Lowes, Home Depot.

Mix it up,  lay on a skim coat, and you should be able to sand in less than a half hour.   Repeat as necessary to fair everything togheter.    Bondo smooths and featehrs well.    Other Bondo products are available to fill any remaining cracks and pin holes.

So Freem, Balsa Foam is a foam product, expanded cell phenolic.

Red,

I've found the best finish to be Acrylic Modeling Paste, which you can get at the art store. Blick sells it, so does Aarons. It's like Acrylic Gel Medium, but a little harder.Sands well, takes paint, not smelly.

EnviroTech is a super think epoxy varnish that is mixed together and then usually poured on to the surface. Countertops, table tops and different shaped clocks are the main places it's used.  I am not certain that it would be the product I would use in this case.  I think it would be too glossy to handle paint, would not sand easily, and be way too thick (when poured it's like 50 coats of polyurethane.  It would however be super smooth.

Sanding sealer either alkyd or water based would probably be a better choice, or model airplane dope. As I'm sure you are aware the object is to eliminate the wood grain.