Here are the measurements for the two types of MMS I own in case you (like me) are interested in creating some custom parts. The measurements were taken with a caliper and accurate to +-0.02mm
Head Peg d. 3.23mm
Arm Peg d. 2.91mm L. 4.09mm
Arm Hex d. 3.20mm L. <1.57mm*
Hand Peg d. 2.00mm L. 4.31mm
Thigh Peg d. 3.98mm L. 4.93mm
Thigh Hex d. 6.14mm L. <1.46mm*
Foot Peg d. 2.53mm L. 4.22mm
Armor Peg d. 2.99 mm L. 3.08mm (cross d. 3.50mm)**
*The hexes were too small to measure, so I measured the spacers that fit over them. But the spacer sticks out a bit over the hex connector, hence the < sign.
Head Peg d. 3.16mm
Arm Peg d. 2.85mm L. 5.27mm
Arm Hex N/A
Hand Peg d. 2.02mm L. 4.31mm
Thigh Peg d. 3.90mm L. 5.27mm
Thigh Hex N/A
Foot Peg d. 2.49mm L. 4.35mm
Armor Peg d. 2.99 mm L. 3.08mm (cross d. 3.38mm)**
**The armor pegs have a cross shaped bit that sticks out around the peg some. The cross d. is the diameter from one end of a cross arm to the opposite one.
Here is a picture!
In both cases I didn't measure the corresponding holes because I didn't see the need. We can assume they are just a bit bigger than the pegs. If anyone wants exact measurements for the holes, just ask.