Sounds like you might be based in Wales. If you are, you should try visiting the National Monument Record of Wales (NMRW) in Aberystwyth:
http://www.themodernantiquarian.com/facility/87
There's a lot of stuff in there that hasn't made it onto Coflein. As well as paying the NMRW a visit in person, you can make a request for information via the following web page:
http://www.rcahmw.org.uk/nmrw-form.shtml
I hope this helps.
K x