Abu. Almost anything will stick to nitrate dope, but the only thing that you dare put over butyrate is butyrate. Be aware that there are two flavors of each; taughtening nitrate and non-taughtening nitrate; taughtening butyrate, and non taughtening butyrate. If you are using heat shrink, you probably would want to use non taughtening nitrate. At least that is what I am doing on my DVII.

On my Spandau's I used nitrate as a sealer and base coat, then Model Master paints over that.

A good quality automotive thinner will usually work, but test it first. The Home Depot stuff may work this time, and not the next, depending on the quality of the particular batch they got.

Les