Lose Lose Decision
In refusing to investigate no one really wins, the PCC members may be considered to be breach of their role as charity trustees. The local home owners still have the possibility of liability outstanding on their land which could be registered at any time as the liability still stands until the property is sold and as a result in the change of the law in October makes it more expensive for one Lay Rector to register against other Lay Rectors (if possible). When an investigation takes place everyone is helped, since a PCC can decide not to register the liability and possibly seek confirmation from the charity commissioners or simply discover there is no liability or find there is someone who will actually give them money if the chancel is damaged. Investigation provides closure for everyone as opposed to a nagging uncertainty.
The Unwanted Research
I took it upon myself to see what I could discover about Hameringham from Staffordshire and the first difficulty was that the place name had changed and was originally called Hammeringham.
My next stage was to look up the tithe maps and there was none and then to look up enclosure acts and according to House of Commons paper 44 there was one in 1772.
This shows that the owner of the tithes was a clerical rector and he got an allotment of land for the tithes equal to 2/15ths of all the new land due to be enclosed. Today looking on the map this land is almost certainly called Glebe Farm.
As the land was given to a clerical rector 'in lieu of all tithes', the liability has long since been extinguished under the terms of the 1923 Ecclesiastical Dilapidations Measure. To be completely and absolutely certain the PCC would need to get the act of Parliament (search Hammeringham here) or to visit the enclosure award and plan at Lincoln Archives. Doing this would confirm, House of Commons paper 44, by looking at the definitive documents but in my experience if an Enclosure is recorded as being a clerical rector or lay rector on House of Commons paper 44, it is a correct record. When sundry impropriators are recorded over a number of parishes in Paper 44 then the only way to discern the details is to look at the records in the archives.
Summary for Ham(m)eringham
There is almost certainly no Chancel Repair Liability in this parish and there is no need to write to anyone but this research should be recorded in the PCC minutes but it might be quite nice to have a copy of the Enclosure plan in the parish..