Just completed my Routemaster. No major alterations but some small enhancements. I sprayed the seats with a matte varnish to diminish the sheen and treated the seat back rails and the grab poles with a 'chrome' pen. Knowing what I know now I'd have done the plated hand-rails and the opening window winders in the same.
Had problems with fit due to some of the diecast frames not being true and the rear frame had to be clamped with a couple of vice-grips so I could fix it with the screws on the off-side! The nearside rear view mirror got broken off very quickly but the weak plastic rod is now replaced with a length of 1.5mm brass rod (now painted).
Added a 'lost' umbrella, and a pop music magazine, to the passenger cabins, and a newspaper and Thermos flask to the driver's cab.
Job done!
Michael