YardyMark

Hello all. I have a pair of LaScala's I bought used around 1978/1979. I recently redecorated my living room and just don't have room for them any more. My question is, what are they worth? Were all Lascala's made the same? Is there anything that would set one year apart from another? Would any info I need be on the back of the speakers? I do hate to even think about selling them. As you see from my purchase date, they have served me many years, many wonderful years.