Things I learned while trying to set the combination on this lock.
There are 3 spacers between the wheels, with keys to keep them from turning. The thin one goes on the outside, after the C-clip that holds the wheels in place.
Successive numbers in the combination cannot be closer than about 20. There’s probably no way to get around this. The width of the movable screw/pins just takes up the space.
You can’t easily use any numbers you want. The pins in the discs are spaced about 11 numbers apart and you can only fudge a number about 3 points or so in either direction. It’s useful to drill and tap 3 or 4 extra screw holes half-way between some holes on the second wheel, and then you can probably get close to what you want. The holes are threaded 8-36 which is not the same as your common 8-32 tap.
You can fine-tune the third number by moving the outer screw stop on the third wheel and also the movable pin on the drive wheel, since one has 9 positions and the other has 10 positions.
There are two slots in the back of the drive wheel where the steel pin sits that locks the drive shaft in place. The alternate slot is apparently used when you want the third number of the combination to be about 20 or less, to allow for some rotation to pull back the bolt.