Creating tuplets with QML

[Tikkoneus]

I've been using music OCR (e.g. Halbestunde) to generate muse files. One of the most common OCR mistakes is to engrave eighth notes which are supposed to be tuplets. (Often this is because the music itself leaves off the '3').

I'm trying to write a QML script which:

1. takes the current selection of notes
2. lets you choose what type of tuplet to convert them to (e.g. 10 notes to two quintuplets, 24 notes to 8 triplets, etc.)
3. removes the notes and re-enters them as tuplets
4. shortens each measure appropriately (e.g. a measure which was scanned as 12 eighth notes but was intended to be four triplets should be 4/4 not 12/8)
5. re-adds any slurs

So far up through 3 works alright. I'm at a complete loss on 4 and 5. I've tried a variety of things but the measure duration doesn't get any shorter (I want the 12/8 measure to be shortened to have an actual duration of 4/4), and I can't get slur entry working in QML.

Any suggestions? Is QML the wrong approach for this? Is there already a tool that does this?