v3.4 for MuseScore 3

Plugin tested on MuseScore 3 v3.4.2. Note that this is not compatible with MuseScore versions 3.3 and earlier because an offset was changed for version 3.4.

Plugin file: tin_whistle_tablature.qml
Whistle instrument file: all-whistles.xml

The font file TinWhistleTab.ttf is attached for convenience from Blayne Chastain and states:

Tin Whistle Tab font is free of charge for both personal and commercial use. Distribution for a fee is not allowed. Please credit Blayne Chastain in any publication in which this font appears with the following copyright notice: "Tin Whistle Tab font © Blayne Chastain / www.blaynechastain.com"