[jimbo]

Nice looking car- wasn't this one of the ones finished by Brian Angliss, maybe I have got it confused with another one...
As far as its' identity as GT40P1086..well, it is described as such in Ronnie Spain's book, and seems fairly represented on the auction site. I believe there are a few cars which are numbered after this which may have been completed by Brian Wingfield.
I don't think which engine it has matters much. As these were race cars, engines were considered to be interchangeable items which were frequently taken out, rebuilt, replaced, etc. This car has an original Boss 302 block which is interesting but neither adds to nor detracts from its' value if you ask me.
If you look at this as a low-mileage late GT40 without race history, its price in the 200K range looks pretty good- especially since a sixties' Mark I just changed hands at Barrett-Jackson for, what was it? over 400K. This would leave you enough for many fillups with Cam2 or the fuel of your choice...
Of course, some of the Mark V cars have been sold for more reasonable prices, and they are better screwed together and nicer than the Mark Is.