I looked at your dulcimer Kitty. I don't think the holes were enlarged as the shafts of the new tuners appear to be narrower than the holes. I can send you three rosewood violin pegs if you wan't to try them. If I lived closer to you, I'd do the work for you. You could remove on tuner and try the peg. It it works then you could remove the others. Email or PM me if you want to talk about this some more.
Ken
"The dulcimer sings a sweet song."