Blancpain bronze is very interesting and mysterious. I also did some research.
The numbering starts at 3220. The biggest number I found is 3225 (the watch proposed by Hodinkee) I don't know a number higher than 3230.
In a post Nicolas talks about one with the number 3246.
We can reasonably deduce that a series of 50 boxes were manufactured.
How many parts are referenced? In my opinion 20 maximum in all versions.
My Milspec military bronze caliber 1361 modified with hacking second hand
(stop second).