Richard Johnson: Jane Seymour’s busy NYC day — pitching ‘Horses’ novel, singing with Malibooz band

NEW YORK — Jane Seymour has good reason to perform with The Malibooz at Parkside Lounge on Thursday. She’s dating the band’s co-founder, John Zambetti. The “Dr. Quinn, Medicine Woman” star will be onstage at the Lower East Side club at 11 p.m. with her guitar-playing beau, who started the band in 1964 with his high school classmate Walter Egan. It will be a long day for Seymour. At 1:30 p.m. …