Yes, you provide power to the gauge backlights (speedo and tach) from AUX.
You bring the stock Gr/R wire to the
GROUND input for NEUTRAL, and power it from AUX (your PURPLE)
You bring the stock Bl/R wire to the
GROUND input for OIL, and power it from AUX (your LtBl)
On the speedo, the
INDICATOR input gets a tap from each TURN L and TURN R, but you will require the use of an inline diode on those inputs to prevent the current from bleeding over through the gauge. Unless you plan to abandon the use of that dash light?
I see you added a 1 amp fuse for the key? Is that the full rating of that switch? That's wicked low...
Several folks who have installed those mini gauges have found the backlight to be VERY bright, and have thus used a resistor to dampen the intensity of the light. You might power them up in the garage at night, and see how you feel about their glow.
The only thing that catches my eye is the double output tap for START. Since I haven't played with an M-Blue personally, is that a new recommendation in the current manual? I'll download and read it this weekend while I fly