2011G6E, you obviously have never spoken to any serious GT enthusiast/ restorer, this is what they do, correct dated horns, window glass, carby, manifold and engine block casting, gearbox casting, diff housing, corret style of fasteners, such as bolts and screws in the correct place coated in the correct material etc etc etc, you can get your glass etched here as well with correct date codes.
I am guessing this guy is doing a big $$$ resto on a valuable car and he wants the original motor back, a lot of these engines were simply swapped for a rebuild exchange from Betta Build or Higginbottom for another rebuild engine, they used to offer a one day drive in drive out engine rebuild for about $1000-1500 depending on options back in the late 80's early 90's, thats where a lot of GT's and GS's were robbed of their genuine engine, no one cared, they were just another car, they were threated the same way people treat their FPV GT's today, as just another car.
He should just do what a lot of old GT owners do/have done, import a correct casting block from the US and re stamp it
As there seem to be a LOT of people who just happen to find their orignal block from some where
Some people did think they were special and looked after their GT, they are the big $$$ ones now, just like some people are looking after their BF GT.
I remember phase 3 GT HO's in the trading post back in the 80's and no one cared.