Simon, the little plate that has the batch/body number was missing from my car when I bought it, although it was some years before I realised this. When I restored my car a few years ago I wanted to make a plate but I only knew the latter, (body) number. Because I keep the register for our local AH club I have access to the recorded numbers of many cars. What I did was look for two cars, one with a lower body number than mine & one with a higher number but with the same batch number. Going on your table, it seems I got it right!