Hi Michael....welcome to the Forum
What is wrong with the engine and what size is it?
I would be tempted to break down the task individually, e.g. take the car to a garage for the engine to be sorted and then MOT it whilst there, then take it to a Trimmers for them to sort the roof. I think you'll find that a restoration company would only outsource the engine work, trimming and even the MOT so why not organise those jobs yourself and save loads of money in the process.
Let us know how it all progresses as have the same car sat in my garage for the last couple of years
Cheers, Trevor