Short answers, pulled from the story.
Northern Songs Ltd formed later that month after a meeting on the 22nd of February 1963. John Lennon and Paul McCartney joined as partners with each receiving a twenty percent share while Brian Epstein held ten percent.
Dick James dialed Philip Jones immediately during their first meeting and played an acetate of Please Please Me over the line. Jones agreed to book the song on his program Thank Your Lucky Stars within minutes which impressed Brian Epstein enough to form the partnership.
One million two hundred fifty thousand shares traded on the London Stock Exchange at seventeen pence but offered at sixty-six pence. Investors oversubscribed the offering massively closing application lists after only sixty seconds despite financial institutions scoffing at the price.
Michael Jackson won the bidding war for ATV Music by submitting an offer of £24.4 million because due diligence was complete beforehand. The deal closed on the 10th of August 1985 allowing him to acquire the Beatles' songs including those published by Northern Songs.
Northern Songs officially dissolved as a company in 1995 when Michael Jackson merged his catalogue with Sony Music Publishing. The new entity became Sony/ATV Music Publishing while Jackson retained half ownership in the joint venture before selling remaining shares to Sony in 2016.