The other stamp is Schrade. I know there was some affiliation between the two at one time. It may be a frakenknife, if so the person that did it put it back together well. Blades are tight with good snap and no side play or blade rub.
Imperial became the owner of the Hammer Brand name & logo in about 1937. At some point, early 1980's ? Imperial became part of the Schrade-Ulster company under Albert Baer. Bonite ID's your knife as 1950's maybe very early 1960's which was before the Imperial-Schrade association, so not a help but confounding. kj