Your photos are none to clear, but from what I can see, those ridge tiles are not too bad. I live at a high spot, where it gets very windy, and mine survived in worse condition than yours, for years. When I got around to it, I simply had the sides buttered, rather than disturbed and reset.
I found my roofer, by simply keeping my eyes open, in the local area. I would sometimes see a guy working on various rooves, around the area, from ladders. Checked his work out, and satisfied myself he was doing a decent job, and waited for him to come down to get his contact number. Since then, I've had him reflaunch the chimney, do the ridge tiles, replace 100 tiles, and even replace the old TV antenna, with a new one. The most he has ever asked for, is £100.