In my experience the LPT people are very helpful and pragmatic.
If I was in this situation and it was my property then I would contact them to discuss if/how to claim exemption for the years in which the property was derilict and then how to discharge any outstanding charges.
If I was in this situation and it was my property then I would contact them to discuss if/how to claim exemption for the years in which the property was derilict and then how to discharge any outstanding charges.