The frame number would worry me quite a bit as it's about 20,000 outside of any known SWD Big 4 sequence. If it isn't registered already then bearing in mind how things have tightened up, there is a good chance of that one having to be ground off and replaced by a 17-digit VIN.
Rik, I reckon the last digit 9 looks odd and added on for some reason. Which would give it the original number 2573 which would be from a batch not having a standard sidecar body fitted......Workshop body?? Ron
