Promoter Sampson Lewkowicz proudly announces he has signed Bangkok, Thailand, slugger Apinun Khongsong to a co-promotional contract, along with Jimmy Chaichotchuang of Kiat Kreerin Promotions. 23-year-old Khongsong (16-0, 13 KOs) is the mandatory challenger to WBA and IBF Super Lightweight World Champion Josh Taylor of Scotland. Khongsong became the IBF’s mandatory by scoring a fifth-round …