Your sitch is a tough one. Like robx said, I think you need a legal custody agreement. Your job & commute will make things difficult. Try to do what's best for your son. Did you ever track down that cell# to find out if there's an OM involved?
Me-39 W-31 S-4 Bomb- 9/5/09 Discovered EA- 9/15/09 Found "proof" that EA is most likely a PA- 10/8/09 W moved out 10/31/09