I've got a tiny horse, but I don't know if it's your grandfather's work or not.
I bought it at the same time, in the same place as a tiny lampwork black poodle. (A charity shop - so they both might have simply come from somebody who liked tiny animals, not necessarily by the same maker.)
The tail worries me, it's 2 bits of glass sticking out in a tail-like manner, not one, the mane doesn't look right and neither do the angles of the legs. They curve in an unrealistic manner. I don't know if it's supposed to be cantering or galloping or even doing some peculiar "dressage" moves!
I have my doubts it's good enough to be his work, but more likely to be something by somebody your grandfather was perhaps teaching, because it's the right sort of style.
I don't have any photographs yet, but if the sun gets through the clouds sufficiently, I'l take a pic for you.
