Apologies for not replying to anyone yet. Got lots to do but will definitely get to some of the answers including sources today!
Regarding catnip - my plants originally popped up in soil that had come from a friend, and I saved seeds. Seeds can probably be bought. I can even mail a few - I’ve shared with friends. A few plants is all you need, and let one go to seed and save them.
I made tincture my usual way - stuffed a quart mason jar (in this case three) with the fresh leaves, added 180 proof grain alcohol diluted with equal amount well water, put lids on, shook them, and put in a dark cool place for a month, shaking every couple of days. Then because I had more catnip maturing, I strained out the tincture, refilled the jars with catnip leaves, and did it again. Also added the flowers if there are any. I actually did this three times to make it powerful, since I really did not need 9 quarts of catnip extract!
After it sat, I strained it out, pressed through a stainer or ricer (one of those cone shaped ones), and stor in dark bottles in a dark cool place.
Thank you for that info.