That doesn't strike me as very natural. I'd say I'll pay him back if I (ever) I see him again.
If only functions for me in a similar way to I wish:
I wish we had more money. If only we had more money.
I wish he's stop drinking. If only he'd stop drinking.
So, my answer to Mikes question, "Can we use "if only" with the simple present?" is "Not normally".