From the PDF parts manual of the 1994 model MC28 I noticed that there was a change in the lower airbox and the grille from chassis number 1006013 to 1006014. Maybe they are incompatible and a previous owner has mixed the parts? Does anyone know what changed in this year?

Also, what's interesting is that the 95' SP has a different airbox and grille and the bands to fix the rubber snorkels to the input side of the carbs is 58 mm instead of 60 mm. Strange.

More differences of 95 SP compared to 94 R, SE, SP:
jet needle holder and spring
carb slide and carb slide actuator
complete assembly of 2 carbs incl. all tubing
levers for power valves
part 12 in the thermostat diagram: 2.6x14 instead of 6x24.
shift drum
clutch cable
...