"Matching Numbers" means what, exactly? Identical frame and engine numbers? That rules out Vincents then. And pre-1950 Triumphs. And Velocettes. And loads more British makes. Or do we mean the frame and engine numbers are the same as were on the bike when it was new? In that case, who knows (or cares) when they see a bike at a show whether the apparently unmatched numbers are the originals or not? Only the factory records can tell you that. Here's an example: 1948 Triumph Grand Prix 500. Engine number 97039R, frame number 20031R. They don't match, but does Mr Concours Judge know if they're correct? I know they are, but only because I have a copy of the original Meriden test report and data sheet signed by Syd Whelpton and Alastair Scobie. So go ahead and show your bike and don't get uptight about it.