Not all carrier engines were 85hp buddy. the earlier brit lumps were the lower 60hp units. It was the canadians i believe who saw common sense and put the bigger 24 stud 85hp lumps in
Andrew. the way i look at it is paint it in what ever you like best, after all it is one of those items that could be easily rectified by a pure'ist at a later date.
how about ford diamond white then get all the bolts exchanged for chrome plated ones...and a nice pollished blower on the top
David (Horsa) would be best to speak with, if going for acuracy bud then paint it that dark blue / black that mercury used.