Actually, it's operated by Sanderson Farms, of Laurel, Mississippi (KLUL). They are a poultry processor, with plants in Laurel, MS, Texas, and Georgia...They also have two LJ31a's (N631SF, N633SF), and a King Air 200 (N635SF). I saw the G-150 up close yesterday, and it is a sweet ride. The hangar was open, as expansion construction is ongoing.
The info as WFBN was provided by the KPHL airport authority, I'm ramp agent for US Airways also spotter/photographer! They didn't say who is the N637SF operator, sometimes the info is "hidden" by someway, don't know why!
Anyways......thanks for your additional infos, I wrote to my book of regs notes for the N637SF.
The pic (very rare for this aircraft) is already in some sites I send aviation photos, I will add this you provided!