The Shortster was built in 1972 only. The X-90 was built from 1973 to 1975.
Here is a good website for the little Harleys. Use the gas tank link on the left side of the page then the tank decals for both models are on page 2 & 3). AERMACCHI-WORLD
Here is a good website for the little Harleys. Use the gas tank link on the left side of the page then the tank decals for both models are on page 2 & 3). AERMACCHI-WORLD