Tower is the house-brand of photo equipment for Sears & Roebuck. The equipment is identical to the famous-maker-brand versions, but you have to be able to recognize the maker's model to know who made it. But in a few cases, it appears that things were made exclusively for Sears, and this meter seems to be one of them.

I believe this was manufactured by G-M Labs, partly because of their long prior association with Sears, and largely because if you remove the front cover, there's are Patent #s on the face (not visible with the cover on)--one goes to a 1939 G-M patent for GM's Standard and Skan meters, the other goes back to the original Weston 617!

Found it in the 1952 Sears Catalog, and that's all I know about it. It's virtually identical to my slightly later Tower Colormeter, the only difference appears to be the cosmetics.

This meter was kindly donated to me, and for the life of me I can't find the person's name in my email archive; and I am mortally embarassed. Please accept my anonymous Thank You.