Just my two cents, but I would stick with newer Premier drums with international size shells. Finding heads you like that fit a pre-international set properly could be hard. I have come close to buying Premier sets a few times, but always passed because of this issue. Last year, I could have scored a turquoise sparkle 60's Premier set for like $250, but I changed my mind. I came real close to buying a Premier set in Canada that was red marine pearl, an international shell kit. They were beautiful drums. The seller would not budge an inch on price, so I turned him down. They must have sold, because they're off Reverb now.
Those Ajax NU Sound drums rarely come up for sale anywhere. I check Ebay UK and British drumshop websites occasionally and they are rare. There's a set up on Ebay UK now, but it seems like most Brits aren't interested in shipping the drums to the USA. All the ads say, "free collection," meaning local pickup. I can't blame them.
I like the raspberry ripple finish on those Ajax drums. There was a set of these a while back on Reverb (they still may be up there for sale), but the seller wanted nearly $2000 for them, which I refused to spend on a special interest kit.
Try finding Carlton and Beverly sets here in the USA. They're non-existent.
Two years ago, I almost pulled the trigger on a turquoise sparkle set of Ajax drums from a guy In Ireland. I loved the look of this set; 22" bass drum, 13" rack tom and two 16" floor toms. I was just too nervous about shipping them. And the shipping charges were prohibitive. I passed on them and regret it now. I could have scored the drums for about $600 USD.