Confused about Black from Tula

[tuttamatta]

I hope that somebody will solve this mystery:
last year I saved seeds from Black from Tula (I purchased the plant at a local well known nursery), since I liked it a lot, I planted a lot of seeds and 25% of them are showing potato leaves, the rest have regular leaves.
It should have regular leaves, right?
So, now what do I do?
Should I save seeds from both (when I have tomatoes...) or only from the RL?
Also, this year for the first time, I'm planning to have a plant sale, so can I offer the PL Black from Tula as such or should I keep them away from selling them?
Still confused, HELP!!!!
Paola