My dad was in aband in the 60’s and has kept some of the kit from back in the day.

He had a Marshall Amp - which we all used to boost our music in the 90’s!!! - which he is now looking to get some info on and possibly sell. At 73 he has gave up the dream of returning to the Fender.

It has a serial number of SL/A 9557A and a stock  number of 1959.

What would be the best route to find out more about the age, etc? 

Thanks