haha ! As always it's your car and your choice, I know i would and can get a bit carried away with some performance upgrades, though you could always keep the original engine cocooned on a pallet ! It's always personal choice of originality or personal spec.
I've been toying with some minor performance tweeks on the 90 Classic i am doing at the moment but trying to keep it as OEM as possible.
I managed to find the OEM 'Range Rover' bonnet and tailgate badges (see the classic badge thread i've posted links there) and ordered those today as mine goes in for strip and paint in a couple of weeks and the OEM alloys for refurb. The tough one seems to be the Vogue SE tailgate badge, but if no luck i'll have a friend with sign company remake them.
I've found a source in the US that does the complete under bonnet decal set as well and i im trying to find a replacement sticker of the underhood purple sticker with multi language text but proving a bit tough too
I'm very impressed with the lvel you are going to.. mine isn't a soft dash and i got lucky on getting one relatively free of tin worm.. some minor scabs under the bonnet and the tailgate, but on the whole sound i'm looking forward to seeing yours done too