G'day ( Australian for "Wassup ?"), Have a 70 model commando, with 71 cases, also have the original cases ( correct No to frame ). Intend on matching up the frame and engine numbers. Question: Can I remove the engine and just replace the lh case and put back into the bike ?, does the rh case have the number or corresponding numbers stamped ?, are they matched pairs ?. ( the BSA I have just done has matching cases, apparently you need both left and right hand otherwise there will be additional oil leaks, you know, additional to all the normal oil leaks. ). Thanks in advance.