For the most part, bicycle bearings aren't that special. I did a Google search for: "49x7mm bearing 45degree" That is 49 millimeters across, 7 millimeters tall & 45 degree angularity.

Does this look like it?

You might check out the Will-Call window at a local automotive/industrial bearing supply warehouse. The guy behind the counter will likely use a pair of calipers from the top drawer of his desk to measure the original & return in about 5 minutes with an acceptable substitute.