Koverall is actually very easy to use. It can be applied with Stix it, but I always adhere mine with dope and that works as well or better. It's adhered around the perimeter of your wing (dont wet the koverall!), then once the dope is fully dried it is shrunk with heat from an iron. Works wonderfully and almost impossible to get a wrinkle that wont pull right out.

The real beauty is it fills with just a few coats of dope and is ready for color trim or overall painting. Tough stuff, it will increase the torsional rigidity of your wing and is very difficult to puncture, unlike silkspan or silk.

Kudos to you for wanting use old school techniques but I think you would be happiest with silkspan on the fuselage and tail, koverall on the wing.