NCGI: pretty sure Pittsburgh wrenches have been made in China and distributed by Harbor Freight for years now, but maybe there was a vintage version of them because a lot of old company names were bought just to import their products to the US. any pictures? that said i bet Pittsburgh wrenches will loosen or tighten a bolt, but i like the old stuff better.
also welcome to the forum. since you are new i won't reprimand you for putting a non pre 1970's tool in the vintage section or maybe yours is vintage and not just rust or neglect. post a few pictures if you can and i use the paperclip just above where we write our posts sort of like attaching pictures to emails.
cheers