If the hydraulics worked well before you split the tractor at the bell housing, your problem is there. As mentioned above, if the hollow shaft that splines into the clutch plate that drives the hydraulic pump has bent the clutch plate during forced assembly, the hydraulic pump will NOT turn. You'll need to split it again at the bell housing to correct the problem.

Please see my response/question on 4/6
Thanks so much!

The drive gear for the hydraulic pump and the pump itself are under the top torque cover. In fact, the hydraulic pump is actually attached to that cover. Had a case once where a small ball bearing was sucked up in the hydraulic pick up tube and broke the hydraulic pump. By pulling the torque tube top cover, you'll discover the problem. Just another point. With the tractor running, move one of the remote control levers. It the motor doesn't slow slightly, there is no hydraulic pressure.

According to all the documentation I can find, my tractor (Hyd pump) does not have a pickup tube. According to my CASE Shop Manuel and the Case Parts Catalog (breakdown) for a 430 Series Case Ag & Utility Tractor (s/n prior to 8262800), a pick up tube was on the earlier dry clutch models. My Hyd pump is actually splined onto the main shaft that runs from the clutch through the torque tube.
When you refer to the torque tube top cover, are you refering to the Hyd control valve assembly that sets directly under the fuel tank? My plan is to pull Hyd control valve assembly off of the top of the torque tube to see if I find the problem.
Really appreciate your help and recommendations!
Note: My tractor is a 440 CK s/n 8244359 - 1964 Model
Mike