I think I have one just like it, worth 50 cents for sure.
Why do you think it isn't a Mac wrench?
Looks like a Mac to me.....
Counterfeiting mac wrenches so they can be sold at thrift stores for 50 cents, what a brilliant way to become a millionaire!
A Google image search could have prevented the need for this thread.
I think I have one just like it, worth 50 cents for sure.

I have some Mac wrenches like the OP's. Any chance they were made by Cornwell?
This thread is kinda funny, a three choice poll to verify the authenticity of a 50cent junk shop MAC wrench. I'm not sure what the op will do with the data this thread generates for him but each to their own I guess.
Plus it says MAC right on the wrench.