Northern Tool has them- I just replaced a set. I do not like Northern Tool for most items; Harbor Freighthas the best selection/prices Except trailer wheel bearings. They have the bearing kit, and the complete hub. The only thing is the dust cap that comes with the kit is too small but easily to find and replace. Measure your axle; should be one inch vs 1.25- NT has both-take your old earring to match up..
I live in Maryville tn we have a shop that only sells bearings I bet they could match some up for you they maybe a little high dollar but the will not be cheap bearings either I will send you a pm with my phone number if you want to give me a shout
A somewhat knowledgeable friend of mine said that bearings are unavailable for the 50's T style TeeNee trailers. This has me questioning if I should restore my Tee Nee or use a perfectly sized modern trailer I have. I hate worrying about trailers when I tow! Or weld the teardrop fenders onto the modern trailer.... lol