One source stated that the Falle combs were made from 0.4 mm stainless steel, "designed for specific profiles". If you look at my avatar, a flat blade blade comb would not be able to traverse the key way, I think each comb must be stamped to fit a specific key way and there probably needs to be a lot of different combs. I think pin spacing is a secondary consideration, because three different pin spacings would cover a large range of locks, ie 0.156, 0.150 and 0.170.
I cut those comb keys on a clunker of a lathe, with about an eight of an inch play in all directions !. I felt that I needed to get some accurately machine cut and to that end contacted a locksmith company, who said that they intend to produce their own, in the near future, so I can either wait until it happens ... or get me a second hand key cutting machine, if one becomes available. It really needs a code cutting machine in order to cut the masters for each key way, which can then be used to make duplicates. A comb key cut for a specific make of lock, is going to be different from all others not only in the key way, but also distance from shoulder for first cut, center to center spacing, deepest cut etc.. Of course, once one has made the masters, you have your own personal goldmine ... until someone else comes along and copies them