Frits Staals 1972 A Reader on the Sanskrit Grammarians is a mine of information on the reception of Skt. grammar by early European scholars. Still available in hard copy from Amazon, and downloadable from Monoskop.
I've been thinking that the next time I teach a course on vyakarana (I just finished one), I'll use Staal 1972 and the new Śabda book that has just come out by Johannes Bronkhorst. That's a solid foundation for students right there.