Peace symbol screen block

At the back of my yard, under an orange tree that is always dropping leaves, is this solitary peace symbol pre-cast concrete block. These turn up every once in a while, usually in back yards, remnants of hippie era book shelves. That's how I got this one some twenty years ago.

Curiosity leads us in diverse directions - let me tell you what I have found out about these pieces of concrete. First - what they are. Called screen blocks or breeze blocks in the trade, they have been and are currently made in a wide variety of patterns. The size of the block pictured, called a 12" Square, is actually 11 5/8" on the sides and 3 5/8" thick. They have a number of architectural uses from ornamentation to, as the names imply, ventilated privacy walls. Currently there are many manufacturers of pre-cast concrete screen blocks. None that I could find are currently offering a Peace Symbol block and access to vintage product catalogs has, so far, been fruitless.

Concrete screen blocks were often used in Mid-Century architecture. An image search will show a multitude of on-site installations. What I didn't find were any installations using these Peace Symbol blocks. It seems unlikely that these were only sold to hippies building bookcases so I'm asking if anyone out there knows of a place where these were used architecturally. I would love to see a picture.