As to your question regarding a flat coat - have you tried Tamiya's XF-86 Flat Clear? If it is not dull enough for you when you've sprayed it on a test piece, try adding Tamiya's X-21 flat base to it - not much, just for an experiment. The X-21 should NOT be used by itself - it's for adding to Tamiya's regular paints to dull them down. Adding a little of X-21 to XF-86 would give you some variation in using these bottles from Tamiya. I have not tried this myself, just read a blurb on the 'net regarding what I've mentioned. If, however, the XF-86 Flat Clear is too dull, than all this verbiage is for naught.