Salmoneye - I have all the stuff to do this on hand (I'm a part time gunsmith) so it is more time than anything else. In all I probably have about $10 in material (the cost of the CeraKote) and a couple hours labor. The gun get dismantled, degreased, the parts to be coated get blasted with a 120 grit aluminum oxide, the parts are degreased again, sprayed, baked and put back together.
NorEaster - It doesn't really dimensionally change much. The coating thickness is about .001 and I've not found it to change anything in putting guns back together.
Sal1950 - I built a holding fixture similiar to a bolt jeweling jig to hold the cylinder so I could get the jeweling brush to hit 1/2 the flute somewhat vertical, then I'd turn it around to reindex and do the other 1/2. It's the first time I have tried jeweling an inside radius and am happy with the way it turned out.