That's awesome! My wife would probably have something to say about it but what a HUGE collection. Watch out with those big glass jugs, sometimes they spontaneously bust. Some of the handmades look original, but there are some contemporary and (possibly polished) ones mixed in.
What strikes me as interesting, is that 26 years ago, some marbles might have been considered common enough to just throw in a jug or jar. Nowadays there could be high demand for those 'exiled' marbles.
Have fun, and if your Grandfather had that much passion for the hobby I'm sure he'd appreciate you enjoying them as well