Apparently the ISS 500 Peugeot, is some kinda Peugeot mtb from the late nineties (most probably 1996).
Not much info made accessible to U.S. citizenry.
It's not supposed to have much vintage value, if not much is known about it. Any mtbike more than ten years old, without much written history, or memorable record, is not very likely to hold much value, other than to benefit from its operation as a bicycle.