I am refurbishing a dozen old Herter's Mallards in between typing, for which I plan on doing a quick story soon...
I too plan on "over coating" them when finished. Over the years I have learned two things. First off, an overcoat does a tremendous job on protecting my toy ducks, and secondly however, it makes it difficult to repaint them.
I have tried a couple things, Krylon spray, among others. My latest thought is this- my friend has a business where they repair and coat new or old concrete with an overlay. This could be a sidewalk, a basement floor, a driveway or even an inside bathroom shower. Anyways, after performing the overlay, they always give the finished product two coats of what they refer to as "sealant". This in decoy making essence would be considered an overcoat. I talked to him about these sealants and was told they make a wide array of different coatings from nasty smelling solvent based ones as well as water soluble compounds, and in different sheens from high gloss to virtually flat. I am going to do a little more research, but am seriously considering using the flat, water soluble version for my over coating. According to my friend, they are used for driveways and sidewalks. I figure that would make the compounds very durable as well as very weather resistant.
My thoughts...
Jon