Location of the helium vents, landing gear mechanism and propellant drains.
at 1/32 the propellant drains are made out of 0.75 mm/0.03 in styren rods and are about 4.5 mm long.

Presence of the propellant drains differs from one LM to the other, there seem to be absent on Apollo 15,
there are 3 on Apollo 16 (like the picture below) and only two on Apollo 17