It would have looked like this.
In all seriousness, though: Looking at FRANKN.STEIN’s post below, it’s hard to imagine someone from the Great Mouse team didn’t have a hand in the whole mustache schtick in Sherlock’s Season 3 opener.
[MBC’s ‘BASIL’ by tales to astonish]
https://observationdeck.kinja.com/homaging-the-classics-1508823806