I did wonder about that Hugh, and i have felt behind the gutter but it feels dry!
Yes will get it re-roofed in the spring so just want a temp repair now.
It looks like a bit of a Clapham Junction of upstands, ridges and valleys ... the water could be getting under the felt from anywhere TBH ... also the right hand section of tiled roof appears to be very low pitch in the last photo resulting in water being blown under the tiles
Agree completely with this. From the photo, there are a few bits that need looking at. The problem with these sort of leaks is that where it appears on the inside is not necessarily where it's coming in on the outside. Not too far from you so if you are still struggling PM me and I'll come and have a look for you. Cost you a coffee and a hob nob.