Don't put a Fender Mustang bridge on a Jazzmaster or a Jaguar
It sucks, and I'll tell you exactly why.
Here is the side view of a Mustang bridge on a Jazzmaster. See if you can figure out what's wrong here before scrolling down. I took the 6 string off so you can really see up close what's going on.
No, it's not the float height, as that can be adjusted use the two black side screws.
There is no individual saddle height adjustment on a Mustang bridge. It doesn't exist. Not on Fender USA or Squier models, anyway.
The only height adjustment you have is from the two side screws for bridge height and nothing else.
Mustang bridge saddles have 3 sizes that somewhat follow the radius of the fingerboard. The 1 and 6 saddles are the smallest, the 2 and 5 middle-size and the 3 and 4 are the largest.
If you don't like those predetermined heights, guess what? You're out of luck.
Here is the rear side view of the string saddles on a Jazzmaster bridge:
Notice the screws that adjust the individual saddle height. It's a beautiful thing. You don't get this on Mustang saddles...
...and that's why you don't put a Mustang bridge on a Jazzmaster or Jaguar.
What replacement saddles do have the saddle height adjustments?
Ask and ye shall receive:
The above is a set of Graph Tech String Saver Saddle Barrel for Mustang, Jaguar, Jazzmaster, and Jagstang Electric Guitars. If you don't like the grooves in the Jaguar and Jazzmaster saddles, you get the Graph Tech set.
As you can plainly see above, they have individual saddle height adjustments; that is what you want.
Yes, I am saying it's the saddles you want and not the entire bridge. While true you will pay more for just the saddles compared to a whole bridge with saddles, you never needed the replacement bridge in the first place.