No, not the same.
The bearing diameters on the spindles are different between 52 and 53. See this bearing info
https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=604816#Post604816That said the mounting ears on the spindle for the backing plate may or may not be different, and that's what matters I expect.
You can probably get around any possible troubles by using the later model spindles and hubs if necessary on your older axle beam, the king pin diameter/kit should be the same.
Ask the seller any questions but even if you try it out on your own I think it could be made to work if it's not a direct bolt on to the older axle.