well i have a genuine ex works grp a car but like most the cars with the good history have their identity kept,like on a new shell or the like as my car come with just a dvla 2.0 3 door log book but was supposed to be a well known car and was converted from lhd to rhd etc..
Tbh i just wanted a good chassis and when i bought mine back in 05 it had some goodies on ,loads of carbon panes and grp a uprights etc etc so was ideal for my new circuit car..
Its now completely carbon ,every panel bar the roof and is wrc front and rear ,xmemebers rear cradle all stru mounts ,everything is now wrc but 2wd ..
When finished it will have 750+hp and with a sequential pneumatic shift gearbox and only weighing at most 1020kg it should be some circuit car..
What you have to also remember is you could buy a motorsport shell direct from ford and build your car to whatever spec with any parts you fancy,a works car is different in many ways and actually heavier ..
cheers danny