Marcus, the JM19 and JM 23 engine books (first column is engine number followed by frame) are at the VMCC and the JM24 frame and engine books are both there...but I don't know if the JM19 frame book is...there are gaps and missing items. The next year's KM23 shared a frame with the KM22 and that book still exists.
I had a look at these for someone, a long time ago, but BSAs are not my speciality and I probably missed a lot. I think that you can still visit the VMCC and view the microfilm copies but they no longer allow the actual ledgers to be handled. Maybe you'd see some clues that others have missed or not been able to interpretate.
If it does still exist, the JM19 frame book will list all the frames and show which type of engine was fitted, together with number.
My personal feeling is that I'd rather have a V5 that reflects the correctly-located and factory-stamped frame number. Did you say if you have a current V5 ? If not and you use the old logbook, it will be retained by DVLA anyway and if they send an inspector, there is a risk that you could end up with a 17 digit VIN stamped on the frame.
Hi Rik.
I think I will apply to DVLA for a age related reg for my M23. I have the frame info from VMCC already and can get a dating letter. The frame info states it was designated as a M23.
Like you say, it is better to be registered on correct frame number, I have a JM23 engine but it needs work. Still, a empire star is a good BSA to have although I will not restore it in anyway.
