Landlord withholding deposit - advice please

I'm looking for any help or advice on an issue we are having with getting our deposit back from the landlord. We rented a 100-year-old house in Dublin for 2 years and 4 months. Two weeks ago we moved out, after giving appropriate notice and having put in 2 full days of scrubbing the place until it was in an immaculate condition.

We were aware of the age and history of the property, and expected that the building would have certain issues associated with its age (damp patches, hairline cracks etc.). These issues would not have affected our time in the house and so we did not raise this as something to be remedied by the landlord.

During our time in the property we had 4 or 5 inspections arranged by the letting agency. Each time photos were taken and the inspectors were very complementary on the condition of the house. Once the inspector even said something along the lines of "I have been coming here for years and this is the nicest I've ever seen it look by far".

In the later months of our tenancy Bord Gais Networks arranged to replace the gas meter, during which time we were issued with a notice that the boiler pipe flue (in place since before we moved in obviously) was in breach of regulations, a hazard to our health and safety, and would need to be replaced. This was brought to the attention of the agency and works were carried out over a two day period. We had to take time off work to facilitate this and did not seek reimbursement or explanation from the landlord for why they were in breach of regulations.

After we gave notice of moving out, the agency arranged for a viewing, during which some prospective tenants raised questions about damp patches. At the time of the viewing the agent showing them around put this down to historical damp and said it would be dealt with. We were then asked to facilitate access for an architect (landlord's father, as it happens) and a builder to assess the damage. They both seemed to agree this damp could not have happened in the short time we were there and was probably historical. The builder then arranged to carry out the works.

We moved out a few days after and a thorough review was carried out by an independent inspector arranged by the agency. He was complementary on the condition and cleanliness of the house, we handed over the keys and left him to it. We have not seen the full report.

This morning we received an email saying that the landlord (who lives n Australia) was not happy with us terminating the contract and was saying that he was advised of works required which were beyond wear and tear.

This came as a complete shock to us and I would like to know whether anyone out there had a similar experience and if there is anything we can do to ensure we get the deposit back? thanks!!!