We have a similar issue - a 900 hour engine 12 years since overhaul on a Public Cat.
At the moment we are able to rent out to the local club or other suitably qualified pilots to help defray cost
Our Star Annual this year will coincide with the change to an EASA 'Normal', we think. Apparently when the annual is done, we will be asked if the aircraft is to be used for Public Transport/Aerial work and the maintenance will be so annotated.
However, because the engine will have reached the 12 year life, we can't actually use her for rental purposes. I don't believe this is recorded anywhere on the documents, just makes it illegal to do so.
On another thread there was mentioned that there were issues of group owned aircraft and maintenance advising that they should be maintained to public transport standards as group ownership could, in certain circumstances, be considered to be rental.
I've had lots of conversations with staff at the CAA and have received no help whatsoever. They don't seem to understand how we work in the real world of general aviation. I had to explain the consequences of the rules to them, and it was like talking to a member of staff in Dixons!
As a result we'll have to look at how we can still allow those who we wish to keep flying our baby to do so. It may mean operating her as a limited company rather than as a group, but it is a bit of a fag.