I have not seen the Mocaco but if it also starts with a low number w/o any load then for sure it is an ammeter. If the meter shows zero w/o load then they have adjusted the meter to show 0.

This is the one:
https://www.dx.com/p/0-36-led-5-digi...3#.XKHoyNhcKUk

Comes in several colors.

The motor:
https://www.dx.com/p/chihai-motor-ch...1#.XKHqOthcKUk

The regulator:
https://www.dx.com/p/super-mini-dc-d...4#.XKHqxthcKUk

The box with a very tight fit for all parts:
https://www.dx.com/p/btoomet-2pcs-wa...9#.XKHrHdhcKUk
A package of 2 is almost the same price as one

And easy to modify:
https://www.dx.com/p/mini-hexagon-nu...7#.XKHsathcKUk