Check out the Tubemonger NOS Picture Library and maybe that can help.
Here is a link to a 1966 6DJ8, which is the oldest Amperex they have before they went to the A frame:
http://www.tubemongerlib.com/gallery2/v/6DJ8/Amperex+Philips+ECC88+6DJ8+1966+Halo+Getter+Miniwatt+Label+1+-+Heerlen+Holland.jpg.html
Here is a link to a 1966 6DJ8, which is the oldest Amperex they have before they went to the A frame:
http://www.tubemongerlib.com/gallery2/v/6DJ8/Amperex+Philips+ECC88+6DJ8+1966+Halo+Getter+Miniwatt+Label+1+-+Heerlen+Holland.jpg.html