Back to the original project- - - -flipping the shafts over and drilling new lube holes- - - - -I'd suggest using a solid carbide drill bit in a drill press, a V block, and making press-fit brass plugs with a sliight taper to block off the original oil holes. There's not enough pressure inside the shaft to require a threaded plug.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!