What can be said about the 4-speed New Process NV833 overdrive manual transmission?

[hatzie]

The MM7 is the 4x4 version.
The MY6 is the 2WD unit you just bought
.
It's pretty much the same aluminum case NP A833 Dodge used in the Ram trucks with a GM input shaft and output spline count.
Make sure the countershaft plug seals properly and the countershaft isn't rotating in the case.. And don't use gear oil in it.

The shifter isn't that odd.
It's an OEM side mount Hurst Competition Plus shifter. You can get them freshened up by Hurst if the shifter itself is terribly loose. If it's not loose clean it up and lube it.
The Hurst plastic bushings and spring clips for the relay rods are available from Summit Jegs etc.