Gidday Neil,
Mine in the rear hub are 2.0" OD, x 0.875"ID x 0.5625" wide. The brake drum bearing is 2.25" OD, x 1.0"x 0.625. For my benefit, that's (2 x7/8 x9/16) & (2-1/4 x 1 x 5/8). Yours I hope will be the same. I have the bearing numbers somewhere, but easier to measure.
The spindle comes out easy, and wheel off, but the bearings can be a bit of a bitch to get out, I made an 'expandable' drift to get in there and push one out, and when it goes back together, make sure you put the internal spacer back in the right way, or it could catch on the rivets!
Can't help with the front, as I don't have a plunger front wheel.(hoping to try muskys technique and just use the rear wheel!!!)
Also if you use sealed bearings they should last for a long time.
Cheers duTch.