is this still usable?

 

No. Those bearing races are toast. Better replace them.

The axle housing however, looks totally fine. The rust looks like surface rust, almost no real pitting. Mine were pitted real bad. I wirewheeled the rust off then filled the pits with JB Weld. Once I sanded the JB weld down they were nice and smooth.

 

This is my first solid axle tube bought it for 200 and noticed this the next morning... and are the races pressed in?

 

Yes, they are pressed in. Just bang them out with a long drift and a hammer. Most people will steer you away from the Trail Gear knuckle rebuild kit because the bearings are junk. They are no name bearings from China. Best choice is Marlin's rebuild kit.

 

Agree... get the rebuild kits from Marlin.
https://www.marlincrawler.com/axle/front-axle-parts

If you limit your tire size to 35" then the strains on the knuckles is minimal and you won't need knuckle gussetting
https://www.marlincrawler.com/axle/f...kle-gusset-kit