I've used automotive (base/clear) on fabric and metal with good results. I've found it much easier to paint before assembly as it is double work to assemble, disassemble, paint and then reassemble. It isn't hard to keep from messing up the paint on assembly, you just have to be careful. You could test fit everything to be sure prior to painting, but I have found that to be not necessary with Rans kits. You should think ahead and if you see a future issue with fit and paint during assembly, then fit everything up to be sure. Hope this helps!
