Hey JoeorElon1986, welcome to the nexus
Nice that you already have 325mg - it's a bit low, but more than 0.5% so in the ballpark of a successful extraction. And it's enough for ~10 nice trips.
More freeze time might do the trick. I would let it sit until it had at least 24h before trying something else.
If there's still no crystals after 24h, first thing i'd try is to evaporate about half of the naphtha, then repeat the freezing with the remaining half. It's possible that it's just not saturated enough.
I don't think adding the new batch to the old one is a problem, but not really sure. Personally i always reuse the naphtha, but never combined the watery portions of different batches.
Best of luck, let us know how it goes!