If you're gonna reshell, do it properly and legally and save yourself hassle in the future - from the police, dvla and any potential buyer.

kid-rs: If it's not a gen S1 shell then it's a replica no matter what numbers are on it. Therefore it isn't worth gen S1 money even if built to a very high standard (which I'm sure it will be). There's plenty of info on the DVLA website on re-shelling if you need it.

slim-jules. Depends on you really and whether you want a proper RS or a replica. Restoring your S2 may cost you more, but it will always be a proper RS S2 if you go that route. If you can't find the DVLA info let me know &I'll point you in the right direction for you to read over and make your own choice.