Sounds good Geo. Personally, I'd seal only the decals on the fuselage and fin, leaving the paint un-coated, and apply a semi-gloss clear to the wings, with the exception of the flaps, ailerons and wing tips. On bare metal finished aircraft, the national markings appear to be heading towrdrs a semi matt, almost semi-gloss, so seal these with a mix of Future and a drop or two of Tamiya Flat Base, stirred in well - but test it first!
Remember the sudden problems I had on my P-47 with this mix? That said, I'd done the same for years, with excellent results, so this might just be the bottle of 'new' Future I have, which I've had for probably two years now, causing the problem, or something completely un-related, such as the possibility of unseen 'finger grease' or similar on the model at the time.
Alternatively, of course, a semi matt clear varnish of your choice will do the job just as well.