Jordan,
There are some differences between the MB/2A/3A tubs, but dimensionally, they are the same. You can interchange all the tubs and all the frames with very little tweaking.
The MB windshield is about 2" shorter than the 2A windshield. This is the primary difference. Because of this, I assume the MB top will work with the 2A windshield as long as you have the matching MB bows, but I have never tried this combination. I'm pretty sure Jpet will have an answer.
Tim