Sorry to reply this late, but just noticed your post.
The General 480 was a made in Drummondville Quebec machine and not an Asian import General International machine. Pretty good jointer.
You can get a PDF of the original owners manual from Vintage Machinery dot org. Not sure if I can post links here or not. Just Google "General 480-1 jointer". One of the responses will take you the correct location on Vintage Machinery.
In any case the parts list in that owner's manual shows that both bearings are 6204-2RS. You should have no problem getting these on-line or from a local power transmission supplier. i.d. 20 mm, o.d. 47 mm, width 14 mm. Rubber seals.
Google some You Tube videos on how to pull the old bearings and press on the new. No point in accidentally damaging the new bearings. A bearing puller is nice to have to remove the old ones but you can get around this with some ingenuity since the bearings are to be thrown away. Just don't damage the cutter-head! Yeah, it's steel, but surprisingly deformable. Ideally you want an arbor press to install the new bearings but you can do it with some ingenuity and the judicious use of a plastic hammer. Provide pressure only to the inner race of the bearing and do it evenly. Often some pieces of pipe (check a pluming supply for black pipe nipples) or even deep sockets will slip over the cutter-head arbor end and can be used to supply pressure on the inner race only. When I did this, I chilled the cutter-head in the freezer overnight and heated the bearings to about 180 F in the oven before assembling. Not sure if it helped but, you know, couldn't hurt.