evidence for build date to get Historic tax?

[ktb76p]

My escort is shown as first registered in January 1978 on the V5 , but from the chassis number and the table that's published in the Burton catalogue I can see that it was built in November 1977, so should be eligible for for historic vehicle tax.I wrote to the DVLA and included a copy of the table from the Burton catalogue but they say this is insufficient evidence and I need either 'An extract from the manufacturer/factory record or confirmation from the manufacturer on headed paper -these documents should provide the chassis number of the vehicle against the month and year of production;or
An extract from the Glass's check book ,which can be obtained (if available) on request from most vehicle owner/specialist clubs;or'
and then goes on to list some other categories which wont apply to me.
Now I could wait until next year but I would rather have the free tax now!
I was wondering if anyone here has got this type of evidence and where from please?
thanks

[Warrior]

Mine was well over that date when I did mine, they back dated 14 months and gave a me a check, if I was you I’d just wait.

[meXEco]

I'm pretty sure they can validate this on Old Skool Ford website.

[Montyman]

I'm pretty sure they can validate this on Old Skool Ford website.

Yep. Old Skool Ford are on the DVLA's V765 scheme and have all the necessary accompanying documents that the DVLA require sight of to prove the date of manufacture.