Because I was curious, I just timed myself forming the stem of one of the leaves: 9 minutes, 30 seconds. So, round that up to 10 minutes. And repeat by 42 for this project as it stands (I likely won't use that many leaves, but who knows -- I'm going to make all of them so I have them).
Cutting a sheet of 8 leaves takes about 30 minutes if the metal is being finicky. There are 6 sheets.
Laying out and tracing takes about 20 minutes a sheet. And there are 6 sheets.
If I do the wheat twist for the base, it takes about 2 hours to form, twist, and wrap the base band.
So far, I have 3 actual leaves done with stems not including the 2 I did for my examples for Kingdom A&S.
Right now, I'm looking at approximately 7.5 hours into the project with what I have done so far, and there is much more to do before I'm done. I'll likely time how long it takes me to chase and repousse a leaf, too, since I'm tracking my time.
(Photos for the algo. Stitch insists on supervising from my shoulders and a pic of my workspace.)

















