Its probably one of the later Messerschmitt as the early ones were very similar to the VS1 & VS2 GS scooters with the cables on the outside.
Vespa GS GS150 Messerschmitt by GLscoot, on Flickr
Vespa GS GS150 Messerschmitt Ulma Wheel trims by GLscoot, on Flickr
Vespa GS GS150 Messerschmitt Ulma Wheel Trims by GLscoot, on Flickr
Vespa GS GS150 Messerschmitt by GLscoot, on Flickr

