I thought it might be interesting to mention the updates the MS380 got from the 038 around 2003
tank caps
tank vent
choke shutter
suction hose
elastostart
chain tensioner
and the round name plate clipped to the fan housing rather than the shroud.
fan housing is different because of the round name plate
the shroud had an unbroken gunsight and a different contour, carb box got a new contour
the tank vent is the 0000 350 5800 mushroom with craters.
ground wire has the connector sleeve we see today
the choke shutter is two piece now 1119 120 2900 flexibly connecting together
suction hose is S shaped 1119 358 7701
fan housing besides whats already been mentioned the air intake holes were enlarged
hand guard screw mounting point now uses a hollow rivet and a washer
chain tensioner went from a front to a side tensioner with the bar plate
***the new air filter has been strengthened 1119 120 1604 1119 120 1621
so I can assume that means the 038 crankcase is different from the MS380 because of the chain tensioner moving from the front to the side.