OK, folks, nearly there now...
I thought I'd share some thoughts that may be helpful to other people building one of these monsters.
First of all, I think it really helps to assemble the fuselage as two full halves -- the seam on top is a lot easier to deal with than steps between the sections.
The nose cone needs a lot of filling and sanding to eliminate the step. If I did it again, I'd build it up with the visor, and then sand it before trapping it between my newly-made fuselage halves in final assembly. I now wonder whether it would be possible to assemble the visor mechanism using Copydex or Maskol to "glue" all the pins into the pivot points -- to give it more stability while you're putting it together, but the first time you droop it, the rubber-solution glue will let go.
Here's something I didn't try, so there maybe all kinds of problems I can't foresee, but it's worked on other big deltas for me (notably 1/48 Mirage
2000s): it might be possible to attach the UPPER wing halves to the fuselage, getting a good smooth wing/fuselage seam on the top, and then add the lower wing. If this works, it'll leave you with a seam to fill behind the lower wing leading edge, but the way it's constructed, you're going to get that anyway -- it's just a matter of degree.I'd thin down the mating edges at the wing trailing edge a fair bit -- to get the engines to sit up in place, you need to lose a couple of mm from the whole set-up, so the trailing edge is a good place to start. Then you have to thin the flaperons, but since there's no detail but ejection pin marks on one side at least, that's not a big problem. You also need to sand down the top of the nacelles at the back -- they have BIG ridges along the top edge of the black part, which need to become paper thin to get the jet exhausts high enough behind the wing. That's the worst fit problem I found.
You probably want to gently curve the lower portion of the leading edge of the fin -- it's very noticeably NOT a straight line on the real thing, and adds a lot to the look of the thing if you do it.
The biggest problem that remains for me, and I don't know what to do about it (but it matters less 'cos eventually it'll hang up) is that the nose wheel leg is significantly too long. Standing on its undercarriage, all the photos I've seen show the fuselage of the real thing is parallel to the ground. As things sit with the model, it's nose up about 10 degrees -- looks like it's on a takeoff roll. I suspect Airfix took the dimensions for the unloaded nosewheel. Trouble is, it's a real s*d to fix, without scratching a new leg, because of the way the thing's structured. The compression oleo looks as though about the right amount of metal is exposed, so the error is in the triangular portion of the strut above it.
You'll also need your best decaling head on -- they're actually pretty good (though a little out of register, natch) -- but they are VERY thin and somewhat stretchy, and bed down very quickly. Not forgiving of mistakes, at all...
Anyway, I hope some of this helps someone else -- it's coming out better than I expected given the fit and engineering problems, but forewarned is forearmed, I'd say. I'm gonna have a VERY close look at any I can see built up in Telford next weekend!
bestest, M.