i wouldnt call it bolt on, it aint that simple,
but i'm in the process of doing this myself. i doubt very much it would work on a standard 1.0 pietro, the ax gt puts out 85bhp standard compared to your 50bhp. I used to have an AX GT and its not just a small engine with a big carb, there is other bits and pieces which are there which produce the big power in the end.
just get a exaust system, weber carb, 1.2 cam and filter on yours, get it set up properly.
or just drop a MA12 in which would make ur car faster than all of the above.