40 year old solar panels - Are they still good? (ARCO M55)

I found two very old solar panels in the dumpster and tested them. They were manufactured by ARCO Solar in Camarillo CA in the mid 1980's. Chances are high that these panels come from one of the first industrial scale solar farms in the California desert. Because of financial problems ARCO sold panels from the plant for US$1000 each. That is $1000 per 50W panel. Today we buy 300W for $200... ARCO was a solar pioneer in the days. They bought the startup "Solar Technology International" in 1977 and built the first megawatt sized solar farm at Hesperia California. The second, larger farm was built at Carrizo CA with 5.2MW in 1984. NEWS: I tested the "bad" panel again with an adjustable load. I got up to 14W and then suddenly it dropped to 5W. So I assume there is a crack in one cell or the connections between cells that opens up in the heat. I guess that was the reason why the panels ended in the dumpster... Images used: ARCO Fuel Station: By The Bushranger - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index... Arco Los Angeles Headquarters: By Minnaert - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index...