I have been also blessed with "donated" old seed. It helps to feed my seed fettish.
As for choosing Black Krim that is not prone to cat facing and cracking, IMO, that's how varieties get improved upon! Good for you. I have saved seed from my Amish paste for several generations, choosing...
I save seed from any open pollinated plants in my garden. Right now, the lettuce is going to seed. There is a jungle of dill weed. And I harvested about 4 oz. of kale seed from the green house. Bean seed is an easy one, b/c they are self pollinating. Tomatoes will more often than not breed...