Any S2 frame will do but the earlier ones with the straight rear upper a-arm match right up. The later style with the offset rear upper a-arm just require changing the a-arm locating-tubes, not a big deal really. A 54 front body section "should" match up but the raised headlamp pods of the 65 won't (depending on where you are cutting). Besides, 65 headlight pods on a 46 would be an abomination and would undoubtedly lead to some sort of wretched existence in the after-life.
Your dash looks way better than mine. On mine the gauges were all corroded and unusable.
The S1 body is much, much stronger, and better built, than the S2 and TC bodies. I don't know much about it but I believe the S1, and perhaps early S2, bodies were not manufactured in house and, therefore, not subject to the usual Lotus production economies.
