How to get long notes to display as long notes in a polymetric piece?

Okay, got a bit of an issue here. I've been working on putting the Minuet from Mozart's Don Giovanni into MuseScore and I've got all 3 meters in the Mozart minuet now(had to make a 1/4 time signature and turn all the bars into triplets and then display 3/8), but I can't get this note in the viola to become a half note in display. Similar thing goes for some of the other notes as well. I already made all but the barlines of the 3/8 itself invisible here so that I could then make the 2/4 look like 2/4 and the 3/4 look like 3/4. But it won't look right if I can't get the 3/4 to display the longer note values. What can I do? Here's an image of what I have and an image of the Mozart score. I'll also send the MSCZ. Bottom staves are in 3/4, middle are in 2/4 and the top are in 3/8.