Hi,
I too had previously tried to obtain these and am the person who was told the library may help linking to Mr Dibble. As Hugo mentioned he sadly died last year.
I was however able to obtain photocopies at a cost as they are not copyrighted. I believe I got them through the Gwynedd Family History Society Library found at
www.gwyneddfhs.org. All my contact was via email as I am in NZ.
There are in fact a total of 4 books.
Rhiwledyn and the Little Orme - Library No 668
Penrhynside - Houses and Families Parts 1 and 2 - Library No not marked but probably 665 or 669
Bodafon and Pant y Wennol - Library No 667
Nant y Gamar - Library No 666
They were copied and posted to me.
Hope this helps