Hey, you owned it before. Why didn't you ever convert it? Maybe you should take a time out and sit in the corner to think about what you've done :shame:
FYI, if it is a compressor with it's own oiling (such as a York) it is really very simple to convert to OBA. All you need is an intake filter, a pressure switch to turn the clutch on and off with a preset PSI, some hose and a tank. I did that on my cherokee and it works great. I think it took a grand total of maybe 1.5 hrs. I even made it so I could quickly remove the tank for portability and tire filling away from the rig.
I could give you a hand with it sometime, especially if you have somewhere to work on it that isn't outside. It really is stupid simple to do it if the compressor is already installed on the vehicle. You can check out the system on my cherokee if you want to see what is requred for it to work.