Bonuses from Maker

somewhere I heard,: Cashapon range is 2-3 above mob drop range
stimulator yields cashapon range,

but not sure... yeah, maybe from Cyanne, but still not quite sure...

The range of any given stat is:
base +/-floor(base/10)

For normal drops, there is a cap at +/- 5.
For Gachapon, the cap is at +7 (not sure about -).

What you claimed seems to imply the following:
Without stimulator: [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
With stimulator: [something?, 0, 1, 2, 3, 4, 5, 6, 7]