Finding proof I have a motorcycle licence

I’m 57 years old, and at the age of 16 became a telegram boy. I passed my motorcycle test with the GPO Newport Gwent.

At the time our licences were put in the Civic Centre Newport and some years later went to Swansea, but unknown to me when I moved my motorbike licence was not put on with my full car licence.

I really have tried hard to find out why it was not added to my licence way back in 1969, the post office has given proof that I did work for them but I still cannot get the DVLA to add it on.

I now want to buy a motorbike but without the licence it’s going to cost me too much.

Can anybody help in tracking down old records?