Hello,
Here is the other Hellcat just finished that I built in the same time as McCampbell machine... This F6F-5 BuNo.58088 "white 36" was apparently very probably flown by Lt Cecil E. Harris from VF-18 aboard USS Intrepid during October-November 1944.
I dilued some Humbrol 106 Grey with essence F (or lighter fluid) at 80%. I applied this "mixture" over the gloss varnish (Future) with a brush and then wipe it with cloth.