You certainly have a beautiful and rare XJS there John....I had a 1980 pre-HE XJS myself and was told that during that year, Jaguar were on strike for 8 months, hence some cars were left outside, no paint, hanging around, etc and this led to extensive corrosion problems. Had to chase mine around with a MIG welder for weeks, even when it was still only 5 years old.
Still have fond memories of it though, such a sweet car to drive and would love one in my garage nowadays