Fill each bearing with Babbit, drill small well-centered hole,
reinstall and enlarge holes in steps with long aircraft drills
available from HD, alternating direction. The tricky part is aiming
each new drill directly at the hole in the other bearing. You could
get drills with 1/4" shanks and an extension shaft so the smaller bore
on one end guides the larger drill at the other end.

Once you have the holes aligned, put each bearing in a lathe with the
drill bit in it and adjust it so the bit shank runs true, then bore to
the size of the actual shaft.

jw