I just hope that you're taking care to get any chips and debris out of the bearing assembly. Radial and tapered roller bearings are not expensive and are usually generally available at any bearing supply house. I definetly would not try this with any precision angular contact or precision tapered roller. It isn't worth the potential cost if screw up. Besides the reason that most bearing sizes are oddball is that they are METRIC
The optimist says the glass is half full, the pessimist says it's half empty. The paranoid in me says somebody put a hole in it.
Remember pessimists are at heart opptomists. They know things can and will get worse.