As far as the question of "how long?", consider that you will cover the airframe which involves priming the bare airframe with dope (I used nitrate) and then attaching the covering. After that comes a coat of nitrate to tighten the covering. Next I added a light 2nd coat of nitrate mixed with talcum powder to fill the weave of the fabric. After that it depends on what you want. Full scale gets a cote of silver primer to protect the fabric from UV. Then comes however many colors you want. When I built a Proctor DR-1 I skipped the silver coat and primed the covered airframe in light blue I masked off and sprayed the background areas for the markings and than used a brush to add the streaky green. I sprayed light coats to avoid overfilling the fabric. The sig butyrate that I used for the color coats has a good pigment content and I was very happy with the results. If you are careful not to over do it you can get a very durable and authentic looking, albeit labor intensive finish. There is an Antoinette in my local hobbie shop that over the years has had some of the lightly built parts distorted by the ongoing shrinking of the fabrick through the years.