Help me find a disc brake master cylinder

Dropped by dads to take a look at his master cylinder. We didnt get to pulling it out, got too busy with other stuff. Took a quick look and it is seeping out the back end. I have been looking online as well as making phone calls as to getting a rebuild kit, or ordering a new one. Seems to be conflicting comments as to whether there are differences between a power vs non power brake master cylinder. Dads car is factory nonpower with front disc. Any ideas??

Thanks
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