Thanks for your kind comments gents.
Graeme; I used the Braz Models conversion fuselage which is, I think, injection molded. The reason I used it is because the -600 is supposed to be slightly longer than the B4 but the F-Rsin fuselage is actually shorter than the Airfix A300. Even if the FRsin kit were to scale out more accurately it wouldn't look right for a -600 to be shorter than a B4.
I chose the paint colours from Tamiya rattle cans using the colour patches on the Hawkeye decal sheet. The top colour is AS-8 US Navy blue and seems just right. The lower colour is AS-5 which is Luftwaffe Light Blue. To me it seems to have a tinge of green in it which makes it not quite right, although the match seemed perfect when I bought the can. If I were to do it again I'd pick a light grey and mix a little blue into it, perhaps even AS-8. We live and learn.