Commemorative 150th 1939 Correos Del Ecuador 2 Dos Centavos Old Stamp

Description

I am not a philatelist. The stamp has no cancellation marks or tears although the bottom perforation is not perfect.
The back looks like there could be a water stain or that the sticky gum substance has started to wear away.
Feel free to ask additional questions and I'll do my best to get you an answer or a more detailed photo.