After reading this post I started searching around for bearings by dimension. I found one and ordered it to see how it would fit. I found it on ebay: https://www.ebay.com/itm/182698869588
15590-15520 Tapered Roller Bearing Set Cone & Cup. These are the outer bearings. The race OD shows the same size as the original. The inner race is bigger than the spindle, but the original inner race actually fills that space pretty nicely like a sleeve. Aside from being a bit wide, it looks like it could almost be used as a sleeve as is.
Is it insane to put a sleeve between a bearing race and spindle? Should it be press fit in so you don't have it spinning?

1949 GMC FC253 - 1 Ton Dually
1966 Buick Wildcat Convertible