Help identifying Opcon/imco supercharger.
 

Hi. I’ve been trying to identify this supercharger that I think is a Opcon/imco but the stickers are gone. What sizes did they come in like L/rev and what size would this be. The last picture show some numbers if that could help identifying it. If anyone has any information about these I would love to know.
https://cimg6.ibsrv.net/gimg/www.off...f7f50f3d2.jpeg
https://cimg7.ibsrv.net/gimg/www.off...05a1bb60e.jpeg
https://cimg8.ibsrv.net/gimg/www.off...e60677683.jpeg