Rich:

Perhaps Peter or someone else will chime in here with a way to add the bars of 3/2.
In the meantime, since it's HowBand's stated request to just have a BIAB file that he can practice with, I think it would be easier to just use megafiddle's method above.

That is, just add a 1/4 measure after bar 22.
I guess you could also split up bar 22 into 2 bars, one bar of 3/4 and one of 2/4
or 2/4 and 3/4 depending on where the perceived accent beat falls.

LLOYD S