Spot the Difference if you Can #22

These two Brazilian stamps from 1900 are easy to miss relative to the differences unless you know what to look for.. There are many varieties in the classic Brazilian stamps that have minor variations, but are often overlooked.  The stamps shown here are Sc# 160 & 160a. But the stamp on the right is worth about 5 times as much as the one on the left..

Look at the stamps below & see if you can spot the difference.
Can you see the difference?

Brazil Sc# 160 & 160a variety

The difference lies in the Frame around innermost oval. The left stamp has a prominent thick framed inner oval, which is easy to miss, especially if you only have the one stamp to look compare to.

Brazil Sc# 160 & 160a variety details
 

 

These stamps not easy to find, and many sellers online do not differentiate these stamps. Look carefully and you can find these varieties if you are patient. I recently found two and am looking for more.
Hope you can find one too.