3461187 isn't the part number, that is the casting number.
The Chrysler part number is 3461176. It was actually a pretty commonly used master cylinder for a long period of time; '71-75 on B, E, C and some light trucks when equipped with power disc brakes.
There are a several aftermarket versions on the market that look pretty similar if you want a new part with warranty, and are indentical in fit and function, such as the Raybestos MC36307.
Also, if you look at rebuilts, you will often find an OEM one with that casting number if a parts store will let you look through a few in their inventory.