I don't know if this pins down the date or not, but that entry reads as follows:There is information on this company at this address Gracies guide to British industrial History. Its states they also did wireless accessories
Newey Brothers - Graces Guide
www.gracesguide.co.uk
I don't know whether this helps or not, but the fact that it uses FETs (Field Effect Transistors) means the earliest date it could have been made was the mid-1960s (when FETs became commercially available at a reasonable price), and that information being displayed so prominently suggests that it was built when FET amps were quite a novelty.Here is a picture of the amp ... Maybe I am wrong with the thread. I will search this forum about informations. Thank You.