We contacted the company in France
that made the tank and were told that the plastic used was identical in every regard, except color, to the diesel tank. They said to change all of the gaskets to a suitable material and all would be fine. Our 47.7 is Hull
220 made in 2002. We have been using the tank for diesel for better than 8 years.
FYI we connected the two tanks together via a single
fuel line and use a transfer pump to fill the extra tank. We then pump it back into the main tank as required. This has worked well for us.