I'm in the process of rebuilding the engine on my 1972 TCS, and am trying to decipher the engine block number / history. The engine number stamp is nothing like a "normal" number. It has just been stamped onto the rough cast block rather than having a "flat" machined down as normal. I've attached a couple of pics - the number is hard to read but it looks like 0331091 or possibly O331091. It is a Lotus block. Any help would be appreciated !