It would be very interesting to see a hard copy of the MA200 styling sketch, and indeed to see if it had any AC Drawing Office markings, a date or signature.
With so little hard material available it is difficult to determine precise time-lines. Dealing firstly with MA200, one account puts completion much earlier in 1963, with the car accumulating a substantial mileage on trade plates. Circumstantially, and no more than that, this account is consistent with Jeremy Davidsons statement that the car originally had a 260 Ford V8 - the engine recorded in November 1963 and on the chassis plate is a 289 - and also by the style of the Factory Ledger entry, which notes purchase tax having been paid. This would usually only be recorded when a car was registered after some road use.
Regarding the connections with Frua, and with the Maserati Mistrale, the few accounts I have seen all suggest the following time line:
a. Special bodied Maserati Coupe by Frua - displayed at 1963 Turin Show
b. Derek Hurlock introduced to Frua by Hubert Patthey - early 1965
c. Preliminary design sketch to AC - followed quickly
d. First AC chassis to Turin - May 1965
e. First car (an aluminium bodied convertible then called the AC427) at November 1965 London Show.
John McLellan also records that, according to Derek Hurlock, there were no body panel design drawings for the AC428 at Frua, just the body bucks. Given the speed at which they produced the AC styling sketches and the first car, that does make one ask whether Frua utilised the Mistrale items in some way for the AC428.
Whilst one cannot on this basis entirely dismiss the possibility of an AC influence on the Mistrale design, it does in my view look pretty unlikely.
