triumph pre unit vin numbers

[thunderbird]

hi all, i have just had my 57 thunderbird mot,d for the fourth year since rebuilding it only on this last mot the tester could not get the dvla computer to recognise it based on the vin number, i have since had a letter from dvla asking for details of the bike and vin number,the bike is matching engine and frame numbers the tester put the correct 5 digit frame number into the computer the only difference i can see looking at the old mot,s and logbook there is an S infront of the five digits on these yet on the new mot it only shows the 5 digits checking the frame myself i can only see the numbers and no S. does anyone know if the frame numbers for the 1957 6t  should have S stamped before the 5 digits on the frame?
Any advice would be much appreciated

[Rex]

No it shouldn't, first digit should be a 0 (nought).
Don't see why there should be a problem though. Seems like once the bike's frame number (anomalies and all) is on the DVLA computer, they don't question it again, so why they'd do this after four MoTs is strange...

[thunderbird]

thanks Rex. it is odd that this is now an issue with dvla unless they have now changed there seach criteria ie vin numbers and not reg numbers are used to bring up vehicle details? it is odd that on all the old mot,s that an S is shown before the numbers, last 2 years its been the same tester/station also odd  that its on the v5c.it was my concern perhaps it should have an S stamped on the frame and that had been lost over the past 53 years! ie i dont want to amend the details if the v5c is correct.i have two other tbird frames and they have 5 digit numbers and no letters before them. thanks steve