s1/2 and 3 are very different .
I bought a remade S2 and it fit like crap on my indian frame (Lamby 150) and legshields (API)
I did a bit of reshaping and did nt use the correct rubbers - I used a toolbox door trim on the back and a thick profile rubber I got off ebay to take up the gap. I also added some trim the edges where the bridge rests on the rear footboards
I`m happy with it now its finished
if you look closely on this photo you can see what I did

good luck