Overfinch did go bust and were bought or at least assets including the name were bought by the Leeds "Dealership", in the words of Private Frazer "we're doomed".
Classic case of life imitating art, all those years ago when LR produced ranger rovers with dire diesels or underpowered 3.5 v8's some bright spark shoe horns in a 5 litre chevy v8 and along with a few other mods a real cracker was born.
I've driven a 5 litre overfinch (89 F RR) and it was stunning, rapid and cornered like a golf gti. I've also driven the 570HSI LSE which was even more rapid, the pity was the cluts who owned it bought it at 5 years old for £38k and shoved it in a garage for 5 years the tin worm was everywhere and it was only fit to scrap.
LR have wised up to this and current L322's can almost be overfinch in performance terms and that has squeezed them out hence the failure of the business, I doubt the Leeds operation will last for too much longer as a vehicle re-engineerer (sic) I would expect them to focus on detailing and power chips, but time will tell.