Hi Johnny
I fitted 3 point belts in my 1975 Turbo so the job is very 'do-able'. From memory where the C-pillar comes down to meet the rear pacel shelf, just behind the rear quarter windows, there is a small triangular section of metal, which you should be able to feel within the headlining. In the centre of the headlining there is a hole with a captive nut welded on the other side. This is the upper fixing point for a three point belt. I bought a static three point belt from Quick Fix Seat belts in London who were very prompt and delivered with a few days - I choose a static belt rather than inertia because the metal on the parcel shelf/bulkhead has not been designed to take inertia reels - later cars I believe had cut outs built into them to take the inertia reels. For mine the upper mounts were not present - but that's more to do with the car being a 1975 and they were not even considered, I checked several cars from the early 1980's and they all had the upper mount point as I used this as a pattern for mine. The kids (seven and four) both sit very comfortably in the back and the car is very comfortable transport for the four of us - it makes weekends away in it possible!
Good luck
Jim Cookson
