I haven't seen very much of these players, but I've read a bit about them. They feature in Clive Everton's book The Story of Billiards and Snooker (the one with the green jacket and players' faces imposed on the red balls), which was written in the '70s and is obviously quite old, but I don't think Clive really described the amateur scene of the '50s and '60s in quite as much detail again as he did there. It’s normally cheap to find on ebay or amazon. I can’t really type out all the stories, so a few quick points:
One interesting point is that he thinks there was nothing revolutionary in Alex Higgins' style of play per se, but sees it as an extension of Cliff Wilson/Pat Houlihan.
Had professional snooker not been so dead, had the media been alive to the wonders he was performing, Wilson could have achieved in the 50's what Alex 'Hurricane' Higgins was to achieve in the 70's. So confident and aggressive that often, if there was no pot on, he would just bang the balls round hopefully rather than play a safety shot; such a fast, deadly, first-time potter that, from baulk, he would take along pink from its spot in preference to yellow, green or brown, so nonchalant that he would pot a ball four feet along a cushion in just the same that he would pot one over the pocket, Wilson destroyed player after players at Burroughes Hall, where his Amateur Championship matches always attracted capacity houses.
The 'new' thing about Higgins was that he somehow slipped through the Joe Davis vetting process for becoming a professional. Clive seemed to think that the support that followed Higgins was to an extent because he was seen as a working class hero, or at least someone rabidly anti-authority, and he was the first openly antagonistic player against the game's authorities and referees. This led to his exclusion from the wildly popular Pot Black and a few other invitational tournaments, which only in turn made him more popular as an 'outsider'.
I've read through various editions of Billiards & Snooker magazine in the late 60s, and they took a pretty dim view of the 1966 World Championship match between Fred Davis and John Pulman. It seems the challenge match was arranged ad hoc. It was only a few weeks before that they decided whether it was to be an exhibition or a World Championship. Billiards & Snooker carried no match report as such - clearly they had sent no one to watch - and it took several months to get the frame scores and added a few platitudes like 'the crowd were very appreciative of the good safety play' or 'they sympathised with the disappointment of the players in the rare poor positional shot', like some school kid who'd been asked to write a report for their homework and were trying to bluff their way through.
The 1969 championship, which Spencer won, is usually heralded as the start of the new era since it reverted to a knock-out tournament, but I think Eddie Charlton deserves a bit of credit for bringing the competitive element of the championship to the fore. He challenged Pulman in ’68 and lost. It's always good to have international representation, and Charlton actively promoted several tournaments (the '75 World Championship, the World Matchplay, and was involved in getting the '71 Championship held in Australia too). Weirdly, the '71 championship was a round robin with knockout stage for the top 4. Charlton finished top of the round robin, but then drew Warren Simpson (see chengdufan's list) in some draw shenanigans in the semi-final. Apparently the semi-final draw was decided before Reardon played Spencer in the last round robin game, so it turned out 1 played 3 and 2 played 4, and consequently Spencer and Reardon played each other. Charlton played Simpson, who was reportedly a very quick Australian player and hardly ever beat Charlton, but Charlton was involved in a car crash on his way to the first session and it seemed to destroy his self-confidence. Charlton was in touching grasp of so many tournament victories – the World Championship in ’75 against Reardon, the SF against Griffiths in ’79, the World Billiards final against Mark Wildman in 1984, and even the seniors in 1991 against Wilson when he had the colours on their spots to win. He so often failed at the crucial ball.
Throughout the 60s, the amateur circuit was more alive than the professional and Billiards & Snooker magazine invariably had pictures of Ray Edmonds and George Scott winning trophies week after week. Gary Owen defended the World Amateur title in 1966 in Karachi, and was awarded the MBE – I believe only the second player after Joe Davis to receive an honour. By the time the game opened up to new professionals in the early 80s, most were past their best.
Since it was mentioned above, I’ll just finish with a match report of the O’Sullivan v Cliff Wilson match from 1992 UK. When I heard they played, I thought, wow that must’ve been a cool match to watch, but the report suggests that Wilson wasn’t too impressed by Ronnie’s behaviour!