I’ve noticed that the 737-500 in aerofly has not even one livery of a current operator. So here are some suggestions (I don’t suggest any liveries that would require modeling a winglet):
1. UtAir
2. SCAT Airlines
3. KlasJet
4. Ariana Afghan Airlines
5. Sepehran Airlines
6. Caspian Airlines
7. Shirak Avia