I fucking did it!
Thomas Bangalter in the Sketchbook app on an iPad Air with an Apple pencil
I initially traced a reference photo to try and get the forms right, and I still feel like the glasses are off, then I worked the different parts in layers incase something happened. Combination of pencil and paintbrush tools at different strengths and the smudge tool.
I worked it like I'd work a water soluble graphite picture so analog art skills definitely carry over to digital.