Ahh, yes two small holes 1 & 3/4 inches apart.I agree oak would be unlikely. The shells at this date are mainly birch with a few in beech. You can also get a beech shell and birch rings or visa versa. People talk about oak and ash but I've never seen anything that looked like that, although I have read that they used those much earlier.
I think John Grey used ash during at least some of their production years but neither it ,nor oak, are shell materials that I would associate Boosey & Hawkes with.
