Not all Jabba The Hutt’s are alike- here is an example of some Jabba coo variations From the Vintage Star Wars Kenner release of figures. Some of the Jabba’s have a more yellowish paint spray over the belly, some do not.
Jabba was one of the ROTJ toys made in Mexico, (MIM) so the US 
L to R coo 1,2,3,
Jabba was one of the ROTJ toys made in Mexico, (MIM) so the US Kenner versions and Lili Ledy versions are very similar, shown in the middle here with the more yellowish belly.
Pix R Johnson