TH350 9.5" stall converter identification help needed

Hello, I came across a nearly free 9.5" torque converter. I got the converter from a guy who bought a th350 transmission with this converter and wanted to use his old converter.
The problem is, there are no numbers on the converter, untypical are the 6 flexplate mounting bolt holes with threads in them, the color is a dark blue.
Does anybody know this kind of stall converter, because I´ve never seen one of these before? I also attached a picture of it.

IMG_1202[1] | Flickr - Photo Sharing!

thanks a lot, bastian