I Really can't recall original wheel size. My guess is 700c as it had Fiamme sprints and Wolber tubs. The 1982 frameset catalogue refers to mudguard clearances with 700c (not 27") tubs. Did Fiamme ever make 27" sprints?
For years I used this frame as a single speed winter bike and have no idea what I did with the original wheels.
I don't pretend to be a purist and used a new "Holdsworth" perforated chainset (in place of SR) and Grande Compe perforated brake levers (in place of Univeral) as looking most like the originals as fitted. I used modern MKS pedals as NOS Campag ones cost an arm and a leg
Restoration using NOS or good quality new parts is something of a money pit, as the total cost, including frame respray, inevitably exceeds the value if the completed project as few people want a steel frame nowadays.
I did try to sell it a couple of times but no takers; I'm not complaining as I undertook it out of the pleasure of the rebuild and breathing new life into a classic bike.
I guess that the Mistral has slightly more relaxed angles and bigger clearances, but is otherwise similar quality to the Special