Trying to confirm these are Bella K500's from the late 70's. Found them in a storage unit packed in 1995 and never opened until 2024. Assume these work as the Bang & Olufsen BeoCenter 9000 and KEF2 speakers all worked great. No info listed on anything but the horns. Small speakers measure 5 1/4 w x 2 h x 3 d. Round speakers are 15" dia. Any help would greatly appreciated. Thanks.