"Finishing" Epoxy is ideal. However it does take 24 hours to cure but gives a nice result.

Followed the link, it looks a great model.

I would consider though, painting the cowl.

Methanol , whether from spilled fuel or just fumes, will attack the FRP cowl and cause it to deteriorate. Painting it, inside and out will alleviate this.

Topflite Lustrkote Cub Yellow will be quite o.k. and match the rest of the model.

If you fly off grass, the wheel spats won't last long. Consider leaving them off if you do.