Shifting a range by an odd number of quavers
I need some MIDI files of Verdi's requiem for practice and thankfully found some here and here. My problem with this one is that it begins with a senza misura measure, which has been rendered as a fraction of measures, and thus what the composer wrote as beat 1 of bar 2 is beat 1½ of bar 3 in the file, and the rest of bars the whole piece begin an eighth too soon.
I could combine most of bars 1 and 2 by creating a new bar of actual duration 19/8 and moving the notes there. But Musescore only moves the notes of the whole staffs, not the ♪s of bar 3, beat 1. Instead, it sets the last ♪ of the senza misura bar on beat 1 of measure 2, inserts a 𝄾 in the place where it should go, and each bar of the rest of the piece likewise begins half a beat too soon. So, to correct this, I would need to move the rest of the whole piece by just one ♪. Is there any way to do that? If I select one of the ♪s or 𝄾s and remove selected range, or split the measure, it changes (as already explained in one of the handbook pages) the bar duration to 7/8, which means that all following bars remain shifted.
Of course, I would be very happy for a solution that fixed the problem with the original file without any of the steps described in the preceding paragraph, but that's probably too specific.
(For future reference: After the shift, it probably will be necessary to join the tied notes; this has been discussed in this topic.)