Never tried it myself but I understand that tissue paper, formed to rough shape them "painted" with dilluted PVA (white glue) & then painted the required colour when dry works a treat.
Before I spray & make a complete cock-up, Revell instructions say white but I seem to recall someone saying that on UK machines the legs, bays etc. were Light Aircraft Grey. Any confirmation one way or t'other?
I think I see what you're driving at. If using tube glue, you'd put it on the ajoining faces. If using liquid glue, I fit the fuselage sides together & then simply brush the cement along the joint. As to spraying on or off the sprue, large structural pieces such as wings, fuselage, tailplanes, nacelles etc. are best sprayed once assembled, filled, sanded etc.
Could be a "goodie" or a "badie". I've built their Wyvern which I found to be pretty good, the Gannet not so & I think there's a thread on here that points out a few flaws with their Scimitar. Expect a price in the £25+ bracket.
It's a while since I built one of these but I don't remember it as being a "bad" kit. However, the engine & it's removeable cowling arrangement is a bit "toy-like" so I'd recommend simply sealing it all up (unless you're into super detailing & can really do it justice).
The most noticeable external difference is the larger wing slipper tanks used by the Mk50, also ordinance which is different. The Mk 50 also had a twin rocket RATOG pack installed in the lower rear fuselage. Although this facility was only ever used for demonstartion purposes it might be as well to incorporate the necessary panel outlines for true accuracy. Here's a good site that may help & should provide all you need to know: http://www.blackburn-buccaneer.co.uk/
If you are building in 1/48, the Airfix kits supplies parts, decals etc.
HTH
Complicated business this, but if IRC, comparatively few RAF Sabres were actually delivered with the hard (unslatted) but all those that weren't were retrofitted as such during their comparatively short lives. Nice model by the way.
Regarding the bulged hatch, I have the Crowood book & it just says that this was introduced to improve escape facilities for the nav "and became standard on the FAW2" which could mean that it was built into all at the construction stage or that it was an add-on upgrade to those that didn't have it from new.