Sad to say my generator of old engravings of leaves did not pan out as intended. My mistake was to isolate systems which are inherently interrelated. Sure I had a nice generator for the general shape of the leaves, for the midrib / petiole / pulvinus, for the venation, for the "sub venation" and the dentation, but as a whole it would not work. A more sensible, but more daunting, approach to the problem would have probably been to simulate the growth of the leaf. It would also have expanded the possibility space of the generator...
I tried to scope down and go for a stylization which required less details but it was not aesthetically pleasing. So if anyone is interested, I published a stripped down version with only the part which are more or less working (the general shape, the midrib / petiole / pulvinus and the main venation) and direct access to all the parameters. http://www.kchapelier.com/procjam2019-aborted/
I'll try to come up with a really simple project to submit by the end of the day.