Use it until it stops working, then buy the XS Supertilt. Honestly, unless you can find the crack that the oil came out of, the first time you take it diving, sea water will leak in as the bubble compresses. That's what the oil in the compass does, it keeps the ocean out. So, you can drill a small hole in the compass, fill it with glycerine, plug the hole with aquaseal, and the oil will still leak out and the ocean will still leak in.
Buying the $30 supertilt from XS will cause you a lot less headache and heartache.
Let this be a lesson. Had I known you were buying it from eBay, I would have advised against it. There are some things not to buy on eBay. Regulator hoses, fin and mask straps, condoms, and compasses. Those are things that "wear out", even sitting in the shop. It's all well and good to buy used, and you can usually get good deals on eBay, but buyer beware. eBay may make you whole again, but the seller did tell you it had a bubble in it. And it leaked more in transit, so the seller would have no way of knowing it would leak in transit.