The economical reasoning is not that important surely?
The car was bought with open eyes and the buyer must be content with the car in his garage.
The effort (time/cost/research) to do this by DIY or 'Barry's Shop'/ Nick Moss/Alan etc is to be seen but will not be balanced by the value when done maybe, but i doubt that matters to the owner.
The strongest thing here is the car is in the public eye, how it is fixed-up will be transparent, so no 2.4S pretending to be a long lost proto of the 2.7 RS for ££££ gain/fraud.
The first 911/912 body was made from sheet metal off a rolling mill, hand formed and developed to the first production car in Porsche's R&D Dept.
Every part required can be made for this car this way in the UK. Any part.
The car will then be a 'barn find' rescued from a shallow grave to a car that will be of considerable interest to the Porsche Circle and most importantly, its owner.
A great project I think being taken on by a keen gent with some resources around him and a good deal of determination. Good luck to him and I would think DDK will be very supportive of the effort.
I just wish he would get on with it!
There are no mega=builds happening on here or are passing-out soon, and some of us DIY restorers need a fix.