Frank, you're right. (THAT oughta teach me to look it up first!) Interestingly, though, about the only color choice for the optional rear seat upholstery that is NOT listed is Geranium; pretty much all the other early trim colors were offered.
<anorak alert>My Third Edition SPC does not list any change of fuel tank part numbers @ TS8637, although it does list changes in the "Strap, tank to body" at 8637 and again at 22014. Meanwhile, a later SPC (exact edition unknown, as that page is missing!) does list a change in fuel tank (possibly at 8637, but that's not absolutely clear). Of course, there was a further change at 60001, but that's not as relevant here.</anorak alert>