It depends on what spares you are looking for. As you probably know Chateau was part of the Tirus Group which went belly up last year. If it is an equipment part then of course you can get that through the supplier, and chassis through ALKO. If it is a body part or window, then that is more difficult in the UK. However, it may be possible to source parts like these through Holland or Belgium where more were sold and there were far more dealers.
God excuse to take a trip over and do some investigating.