This is a May 6, 1969 Souvenir Sheet (SS) for stamps identified as 168 to 179 (12 stamps) in the Scott Stamp Catalog. First off, I apologize for the poor quality of the photo - I used the optimizer on the website, but it really affected the quality!
There is no glue on the back of this SS and I found no notes in Scott that the stamps existed as such. In addition, note the order of the stamps on the sheet. They jump from 10F, 30F, 50F and 25F on the top row. It doesn't get any better with the succeeding rows, with the lowest value in the set being the 2nd stamp in the 3rd row.
It's not like these stamps have any great value ($6.00 per the 2014 Scott Catalog), so I'm not sure if what I have is a genuine souvenir sheet or not. Can someone who knows something about Chad stamps please help me determine if this SS is a genuine postal item? Thank you if you can!