McCulloch supercharger looking like a S.N.60 but serial says V.S.57

Hello, I'm just trying to find out more about a centrifugal blower I inherited, it's strange, when I researched it I found that McCulloch started with a larger version with a set of gears between the turbine and drive pulley called the V.S.57, and did away with that for a later more compact version designated S.N.60. Well, my blower looks like the latter but is stamped with V.S.57. What gives? Any info would be greatly appreciated, I'm going to upload pics right now. The orange doohickey is the mounting bracket, specifically the idler arm tensioner. It's pretty cool and cast iron construction, so older than the hills. In case the serial on the blower was hard to read: ROVS 57 A 7333 ROLs. (The last "s" looks to be in lower case for some reason).

 

An intro here might be a bit different, and this question then posted on the site. Looks like a VS with the front clutch ***embly removed, and without the front cover from an SN. I’ve owned VS, SN, and VR’s, but never seen one like that. There’s several guys out there who restore these, but I’d start by calling Craig Conley at Paradise Wheels.

http://paradisewheels.biz/power/superchargers/

 

Thanks for the info, was that a thing? Mixing halves of these superchargers? I wonder if it will even work. I did have it apart, and it doesn't look like anything is missing, the turbine rotates smoothly, albeit with some effort applied, I actually looked up that company, and at some point I'd like to hire them to rebuild the thing if it even needs it. I'd like to paint it blue and build a Ford 302 for it to make a gt350 clone motor.