The only place you're going to find any information is the dark web. That's where I got started. Hell, anymore I spend more time on the dark web than I do on the surface web. You won't find anything on the surface web about how to make it. You can try the Anarchist Cookbook. I haven't read it in forever, but if I remember correctly it can give you a good base to get started. But you have to get the actual original book that was printed in the 70's. And that one is next to impossible to find and expensive as hell when you do find it. The reprints, give decent information, but they have been edited by the government, so it's a crap shoot there.
I hate to be another annoying person to bother you, but I'm very curious about how you manufactured cyanide and any resources you may have to help me do the same. I have been trying to find information but it's difficult to come by.
I found several sites on youtube. The one I tried definitely worked but it was both impure and very little. If I actually did bookmark I will send the link.
By the way Cherry Laurel works too, but figuring out it's strength proved impossible. It numbed the mouth immediately and I did fall to the floor, but that was it. Mind you I just put my tongue on it...saving the liquid for a later date. When I got home from shopping the container had been emptied down the sink...ah well...I am sorry to all though, this was a long time ago and you would have to check 'miscibility'. The recipe should be found in an old volume. They used to use it as a cough medicine...cherry syrup I believe was the name and yes, some did die...
The pits from fruit are very iffy. Each plant retains a different amount of another chemical that reverts into cyanide. In my opinion the Yew Baccata is the best bet, but often proves to be a nasty death...Sorry I used to be a horticulturalist. Can't spell...duh.
Two strokes have emptied much from my head...but all of this information is available. Try pharmaceutical codex from about 1950. An inheritance from my father, which I can no longer read...sigh.