I've searched for the strainer at the following sources and can't find it. My guess is it's knock off from back in the day? Aluminum shell with 6 lugs might sound interesting right?

www.coopersvintagedrums.com/ludstrainers.htm

www.coopersvintagedrums.com/slingerlandstrainers.htm

http://www.coopersvintagedrums.com/leedylugs.htm

Something that old could be one of the long-gone brands. W/A, Lyon/Healey, among others. The rim hooks are cast,and the strainer as you mentioned is unique. Someone will pipe in soon I'm sure.

I wouldn't think that was aluminum, shell will probably clean up nicely. What is the weight of the drum? Brass is heavier. Unless someone put older styled clips on a newer aluminum shell to make it look older. I am not familiar with the throw either. Rims usually pit up on the older snares. Someone on here will chime in and help they always do. This is the learn something new everyday site that I visit daily for that reason if not any other.

Wayne