Good project. I an retired local 150 IUOE brother. I have a 1950 5UD2 and a C-45 LaPlante-Choate 3 yard scraper. Have fun with you new toy.
Chuck C

For some reason Cat uses steel bushings for the vertical shaft. An ivitaation for corrosion. If the bushings need replacing I would consider brass replacements.

This is what your carrier rollers would have looked like originally, they are a center mount style.

bushes are available for that hyd control shaft when i got new bushes for mine i had to get it copied as only one was available world wide the bushes are pn 7f3583 there is also a seal 1j2382.
i can post a scan of the relevant page in the manual as i have a copy. mine covers hyd unit serial no 6w5001 onwards
use plenty of penertrating oil and deisel on that shaft idealy soak it in it. all the hydrualic fittings are SAE code 61 you eithe need to recyle the clamping flanges or make new ones as they have now gone 4 bolt to cater for the higher pressure of todays systems these old things max out at 1200psi.

Welcome to the sickness that is old Caterpillar. Retired IUOE 302 at 52 and have been collecting, playing with and rebuild old Cats ever since. I started with 1 d2 and currently am down to 3 d2, 5 d4 and a112 grader. Be careful the sickness creeps up fast

oldmachineryitis,
noun,
a disease usually afflicting the male human being allthough some female suffers do exist (this depends largely on if they spent time growing up around male family that was afflicted)
it is very catching particularly as young boys and can be a life long condition. many retirees get it particularly if they worked with heavy machinery at work.
the condition isn't known to be fatal, but the all consuming obssesion may drive female partners to homicide due to neglect. no cure exists.