If you have MF2.something.ipa in your iTunes you should be able to revert, I haven't actually tried it but if you delete MF3 from your iTunes library and then copy the MF2.ipa into the same folder it should load onto your iPad when you sync. It doesn't really matter which version your DL has as it can be persuaded to load the firmware from whichever version the iPad connected is running.
RR, I'm not sure any iPad with iOS5/6 would load MF2, unless you have a 1st gen iPAD, I think Apple would force you to update to iOS8 rather than load an old version of MF. i'M ser.... sorry, I'm seriously considering a jailbreak on my iPad to get out of the Apple straightjacket, I did try it with my old iPod Touch and didn't find it an especially good experience but if I do I'll post my thoughts.