I came really close to buying a turquoise sparkle Ajax set this summer from a guy in Ireland, but with the high shipping cost, it wasn't worth it. He assured me the drums would take modern heads, and the photo showed them with Evans and Remo heads on there, so that wasn't an issue. I loved the color, and the drums would have been a real attention grabber on my gigs. I have been quietly looking for an Ajax set since, mainly because nobody around here uses them, but they'd have to accept today's heads, as I refuse to go crazy hunting for heads that fit.
I'm in Ireland too, but I'm not the same seller. :)
I believe that the earlier Ajax are the oddball sizes. These were around before the advent of plastic drum heads. It was all calf heads and odd sizes. I'm talking about European drums anyway.
I'm with you with the modern heads thing. It's a must for me. I think 60's Ajax might take those Evans level 360 heads. I'm no expert on Ajax, but since I came across this kit I've learned a few things.
They're nice, but I prefer Olympic Drums as far as British drums are concerned anyways.