I wonder is anyone else had this problem. I took my car for a prebooked MOT test which had to be cancelled for the sole reason that the make and model couldn't be found on the computer system. This is a car of which around 1,400 have been produced from 1965 to date in four countries. One of them completed the Le Mans 24 hour race and another holds four current UK speed records. But VOSA's computer apparently hasn't heard of it and can't even get the details from the DVLA computer. My car is properly registered and has a new style V5 document.
Oddly enough I recently ad a Mini Jem tested and there was no problem even though it is a much rarer car that hasn't been made since 1976.