Remember the fiscal stamps that were overprinted back in 1934...  Just a word about them:   SCARCE!  There were 10 values of these fiscal (tax) stamps and they are extremely hard to find...  That is good, in that it makes it unprofitable for anybody to make a fake surcharge to imitate the 1934 stamps.

There were also surcharges on three of these fiscal stamps in various configurations.   The surcharge was "O.K.T.E." and it was a postal tax stamp.  The surcharge comes in several variations.