No reason to try to find the correct year, that engine in there will do just fine. I would turn my attention to that qtr. though... it looks like you're going to need a little more than just the qtr skin to bring that back. An outer wheelhouse is definetly a possibility.
My opinion of the car is this... having built a number of these cars during the past 20 years, this car needs a total resto. If you absolutely LOVE this car, then yes, go for it. But you really gotta LOVE it to be in it for the long haul. So far, as mentioned you will be doing the qtr, floors, rebuilding the engine, painting the entire car, completely redoing the interior, at least the inner fender on the passenger side as well as a complete refinish under the hood. If I were you I would get a good look at the frame rails, torsion bar crossmember, rear spring perch area and front frame stubs. This car is basically a total resto, and I don't want you to kid yourself that it is not. If you LOVE this car, then go for it, it'll be a nice car once you're done, but if you ain't in LOVE, then you may want to seriously consider this fact before you plant any $$$ for it. You're looking at about 15K to completely refinish this car, and maybe more if you have to hire it all out!!! You good with that???
Anyway you decide, I'd like to wish you luck. I LOVE the early A's, but even I would have 2nd thoughts about this one!!! JMO, Geof