Thu Nov 21, 2013 4:56 pm by MBI
You're right, they don't use standard depths and spacing. The one pictured is the most common one I've seen.
The guy I was working with had about ten different patterns he'd come up with. I cut keys and he tried them all out on two or three different keyways and quickly narrowed it down to about 5 patterns that sometimes worked. The rest were garbage. I cut more keys, one of each of the five patterns on the two or three dozen of the most common auto blanks, to see which of those five patterns worked best for any particular keyway/lock type.
The final goal was to make something of a "master set" of marshal keys for lockouts, with the fewest possible number of keys you needed to carry, with only one or two of the most effective patterns for each blank. We made some good progress before my partner had some personal problems that made him abandon his end of the research, and in fact his participation in lockpicking/locksmithing forums entirely. The problems were bad enough he even let the forum we were building languish and then didn't renew the domain name, or return my messages offering to take it over so it didn't die. I hope he's doing ok but I haven't heard from him in years.
In the end, I have some of the data from the research... buried somewhere in my boxes from when I moved, but I don't have anything close to that final list of keys we were trying to assemble.