The best source of ASC McLaren info was Sandy Block. Unfortunately he passed away a couple of years ago. He tried to pass on much of his knowledge at this site
http://www.ascmclaren.orgSince there were so few hatchback cars done, and few discussed information was limited. There are a few followers on the site who will probably be helpful.
Two things to do first:
1. Check the buck tag for ASC McLaren (2 buck tags)
2. Check the VIN number. ASC special ordered cars start with MHBP. Regular production cars were different VIN prefix but some were also converted by ASC.
3. Next would be to get the Emminger report as that would show it going to ASC for conversion.
4. Most ASC cars also contained a Ford Parts List that was thrown in the car at the factory for such things like the SVO steering wheel, etc. This is not always an easy piece of paper to come across but I believe they were delivered with the car at the time of dealer delivery.
I hope this helps.