Technically nothing is a like for like, they no longer make the chassis, or reproduce it, they do a reproduction one, but its still missing parts on it, its cheaper and faster to build it that way, it's the only way I can get power steering on it, and it be legal on the road, same for the mounts, you can only do certain things and for it to be roadworthy
What I mean is you will lose historic status due to the alterations...a reproduction chassis is a copy of the original a modified S2 chassis to fit a V8 is not a reproduction copy...