Welcome to the forum! Squeaks can be tough to chase down. It seems the most common squeaks come from the drums, but I just had one at the pedal shaft a couple of weeks ago. Here are some points that I like to lube:
Pedal shafts
Drums (inside and outside)
Chain links
Sprocket shaft (front and back rotating parts, both sprockets)
Idler pulley
I haven't looked inside the MD 180 yet but there should be no moving parts that would squeak in normal use.
I also shoot (with silicon spray) the boom rotation points (accessible when the fins are horizontal) and cable openings. This makes the reverse process very easy.
If that doesn't do it, make sure your shoe isn't rubbing against the crank arm.
