Help Needed In Identifying Paraguay Aereo Stamp...........

Hi,
I'm having difficulty finding a home for a Paraguay Aereo stamp. As I can't post a pic, I will do my best to describe it.......
It is a horizontal commemorative size (33x23mm), blue/purple on white. It is for 18.15 guaranties. The illustration is of 3 men accessing books in a library situation. In the upper left hand corner is the Lions "L" in a circle with "Lions International" around it. Top right is "Correo Del Paraguay" with a small "Aereo" under it.
The bottom center/right reads "boda de oro del leonismo nosotros servimos centenario de la epopy a nacional 1864-1870".

I've gone thru two Scott's catalogues and can find nothing like this. While the stamp appears to be from the 1950s era, I could be way off.

Your help and expertise is greatly appreciated!

Thank you!

Sounds like Scott 1023 18.15g violet? It was issued in 1967 and is not air post, so I am not sure why it says aereo.

ps - I just noticed that the Scott cat says that 1022- 1026 are airmail.

You beat me to it!

Yes, 1967 Scott 1023 18.15g violet "Library-Education" CV 20c

This is part of an 11 stamp set for the 50th anniversary of Lions International.

Wow, once again you guys save the day.

I honestly spent a lot of time going thru the cataloge. Like a couple of my previous "can't finds", the pic is not specifically shown and one has to read the fine print to flush out the description. I'm not complaining of course, but it is difficult for me to acknowledge "I can't find it" and then learn that it is there.

Thanks all!!

Hi again,
My worldwide collection is thru the mid 1950s. I picked up a number of albums for that time span to build up my albums. What I'm finding is that some of the folks put stamps in the album where they didn't belong. Said another way, this 1967 stamp was in a Scott's Vol. 2 album - which of course is for the 1940s time period.
Again, Thank You!