This was quite something into the early 80s.
So far as I know, it dated back to the times of full employment and when most working class men on Tyneside were employed in shipbuilding or other heavy industry. It was a kind of party for men who "balled up", left work at midday, on Christmas Eve. It became institutionalized a bit when working men's clubs started to put on a buffet, a blue comedian and a couple of strippers.
Looking back, it was part of an oral culture - you'd never see a sign advertising a ballers' balls. Instead, you'd arrange it with your mates and male relatives a day or two before, and it was always dependent on your being able to get away from work, which in those days depended on the system of the "pass out" and an amenable foreman.
I'm not sure about the etymology, or even, frankly, the spelling. It could be bowlers' , I seem to remember some people pronouncing it that way. According to the OED, a baller is one who attends balls, or one who plays ball-games, (actually, that latter would make sense once-upon-a-time, using the excuse that you needed to be away to play a seasonal game of football in order to secure your pass-out?
I seem to remember hearing it in connexion with the verb, to ball up. The OED gives several meanings of the phrasal verb, the only one it common usage today is to fail, to make a mess of, but on Tyneside, that was always to balls up, so I don't suspect that usage. There were ballers and the verb ball-up in the iron industries.
Perhaps the likely origin is the meaning like our contemporary to party, so a baller is one who wants to ball and the pub or club will lay on a ball for him. The party-goers' party.
To some extent there was a portmanteau word, because of the sexual meaning of the verb, and the fact that a good ballers' ball featured strippers. Do you even get strippers anymore? I always felt very embarrassed by them.