Its a small world- I had a 74 Triumph Spitfire about 15 years ago. Very light and very easy to work on with the flip up front end. I never bothered to check the mileage when I had it- I only cared about power and cornering back then.
Its weight and low frontal area would make it a great FE project car.
Here's a member with one:
http://www.gassavers.org/garage/view/1043
I am puzzled by the new 600cc Honda car- is it the Fit? With such a small engine, I figured the mileage would be in the 70's or so, but it isn't- any thoughts as to why its not much higher than civics and metros?