Modern day uses for the Kenwood Km-209 Power Amp?

I have a Kenwood KM-209 Power Amp, KC-209 Amp Controller, and a KT-89 Stereo Receiever. I see a few people mentioning that they still use these components for whatever purpose. Do they have a place in modern day audio or home theater setups? They were given to me by a friend awhile back and i've been considering selling them. Any idea what they are worth?