Coha,
As I suspected before you managed to load the whole pic, it's highly unlikely that brass "handle" is original. I don't know of any pipe wrenches that used a loose brass tube as a handle, and it looks like a PO (edit: "prior owner" in hobby lingo) put that on as a replacement for the original, which probably split and fell off. The "A67" marking with its hacksawed-off "A" is likely associated with the nomenclature for brass tubing.
As for mfgr's ID, almost impossible without branding. (edit: That "5" looks after-factory.) What you have there is an Improved Stillson pattern, and it was licensed to everybody and their mother by Walworth, who held the rights. Ridge, Erie, Plomb, etc all made them or had them made for them. Someone more into Stillsons may be able to identify it from nuances in the features, but it would be an exercise in overkill, because of how common these were. And completely unmarked probably means 3rd party retail.