I just received the $40 Beck Arnley 072-6331 Brake Master Cylinder from Rock auto. Link to pics below (no plug in the 3rd hole on this one). Sorry no side-by-side, the other is already at the shop.
https://www.dropbox.com/sh/4gyri7z7s...N9vY_rhqa?dl=0
Definitely, need to check the bore sizes for compatibility. Looks like some manufactures have updated models with smaller bore sizes.