You don't need to know the factory setting to determine optimal lever height:
1) After adjustment to max height, set the loose diaphragm in place without a cover and tap it very gently with your finger. You are trying to determine the space between the diaphragm at rest and the lever below it. It should be about 1/32"/<1mm. If there's a bigger gap with the lever at max height, see step #2, or get a new diaphragm.
2) Once that setting is optimized, pressurize the reg, and slowly screw on the cover: if your reg begins to leak as the cover goes down, the anti-friction ring and cover are squeezing the diaphragm slightly so that it's beginning to depress the lever, and the lever needs to be lower. Go back and drop it a hair and try step #2 again. Generally only the regs with wide antifriction rings have this problem, and the XIV doesn't have this issue (since its cover doesn't screw down - with it you check by just dropping on the faceplate and squeezing it shut with your fingers).
After you're done, you can usually tell if there's a gap by gently depressing the purge button with your ear up close to the reg. You can usually hear the tiny click as the diaphragm disc hits the lever, if there's still a space, before the reg starts to hiss. Anything from 0" to 1/32" is usually okay.