We have this car in our barn . . .

This brings back memories!
My brother had (and still has) a '77 Arrow GT that was very similar to the one you have, except it was blue with white stripes and came with the 2000cc engine.
We drove that car for years to work every day in the early to mid '80s and wore out the engine, then he bought one identical to his that was written off and put the 1.6 out of it and wore that one out.
Then he bought a 2.6 for it and put that in.
When the body finally rusted out, he found a '79 Fire Arrow with a bad engine and swapped out the engine from the GT to the Fire Arrow.
he still has the Fire Arrow and drives it once in awhile, and the GT is parked in the back 40 to be used as a parts car...........
He gets lots of looks from people young and old, and nobody seems to have heard of a Fire Arrow before.

Dartnut, Holy Cow!! A lot of work, but what a cool way for your brother to continue to hang on to a car he must love!! Great story!!