Had another roofer take a look and he's advising two things...
1, Re-point the chimney on the roof side and remove/re-bed the pot - showed me the pictures and this definitely needs doing, poor condition and cracks - quoted £250
2, The felt runs beneath rather than lapping into the back gutter so if there's water getting through the tiles it'll run into the loft rather than into the gutter - again, showed me pictures - quoted £200 to remove felt/batten in vicinity, re-felt and re-batten ensuring laps into gutter
I should be able to check if water is getting to the felt from inside the loft so at the moment not convinced I'll go ahead with 2 as while appreciate not optimal might not be the problem.
I've asked him to send me the pic of the gutter he took and will share on here if he does for opinions and hopefully settle some of the discussion hah!
I'm waiting on another opinion, but difficult to get roofers at the moment round here so may not show.
Couple of things that come to mind are whether the back lip on the gutter is high enough to stop it overflowing off the back in heavy rain.
And then from the earlier picture of the stack from ground level it's not clear that water can flow out of the back gutter down round the chimney into the gutters. It looks like it might be obstructed by the flashing so the back gutter just fills up? Difficult to tell from the pics and probably unlikely that two different roofers wouldn't have picked this up (maybe not!).
Yep, he's been and is very apologetic. He'll do both the pointing and lap the felt into the gutter for the pointing only price as an apology.
Got very lucky, ceiling plasterboard is foil backed so the rain ran to the bedroom downlight and dripped on my wife which woke her up. If not for those two things the ceiling would have come down I'm sure. Just took another 11 litres of caught rain out of the loft!
looking at the last pictures I see battens that are dry. Chances of it being an actual roof leak is low.
Just above the holed felt it looks like possibly a live water mark coming from under the felt lap. If it is, then it can only be running down the back of the felt under the lap to the outside.
The lead work I see three pieces, an apron and two other pieces. obviously there are two pieces for a reason, ones not wide enough or split or something.. Back gutter needs replacement