An old beekeeper I know has something very close to these, He doesn't remember where he got them but he has had them for years.
They came with just the plastic sides,you made your own wood top and bottoms. Of the ones he has used he has to only occasionally replace the wood..
He has a few cases of them but I cant get him to let me buy them 
Is there anyway you could find some sort of marking on them to find out their origin? The biggest impediment for me to make frames is the time to mill all the intricate pieces. Straight top and bottom bars would be a breeze and I could easily crank those out by the 100's if those plastic pieces could be had cheap enough.
Hey Jack, did you hear that? Yet another good use for plastic! 
I found out more info on them.
He told me that they were made in europe and Betterbee sold them, this was 10 plus years ago, He only bought them because they were on clearance and so he bought a few hundred of them.
The other thing he does is he does not glue or nail them together so all he has to do is pop off the sides and throw the rest into the solar melter.
