Okay, I put the fuse together finally and did the nose modification. Putting the fuse halves together with the wing blocks loose meant I had to rope the girlfriend in to clamp the fuse while I held the wings up. A nervewracking moment (GF: what do I hold? What do I hold? Droidmilk: That!! That!! Quick, we've got 7 seconds!!!) and one that I'd been rehearsing in my head for nearly two years, lol. but it came out OK.
I put a 1mm styrene shim between the fuse halves at the nose end, to shallow out the slope of the upper fuse a bit. I shallowed out that upper fuse slope even more by building the surface up by a further 1mm with putty. I also thickened it slightly in the plan view to get a more 'square' front to the upper fuse. Then with the nosepiece I decided not to p*ss about and really WENT for it, placing it a full 5mm beyond the fuse and filling the gap with styrene, epoxy and putty. The rear upper of the nosepiece is also built up by 1mm of putty. I'm still working on smoothing all the contours, but I think they'll pass, though raking light is never gonna be too kind to them. I can live with that though; I have the more assertive X nose I was after.
First pic shows my blu tac tack-together, the rest show the actual job. Cheers for looking.