Do you know if he painted in PU or is still in gel-coat?
It is still in the process of refinishing with Urethane paint. Should be done soon. It's taking a long time!
The person doing the refinishing told me that many sailplanes made in Europe and eastern Europe in the period around 2000 to 2006 did not have UV protection in the gel coat due to some substance being banned because of environmental laws. He said he has refinished many from this period.