Cats are probably thinking, I'm not going to sleep till he does, kiddies are going to sleep, hoping it was all a bad dream, and mum will be back tomorrow!
You'll probably need a scrap of 3x2 between the batons to raise the hip iron to the correct height, and if you grind the back of the tile it should sit flat.
8 ft length of 3 x2 or similar will catch half a dozen of those rafters if you sister it to the lower side of that puny purlin.
If you are screwing through that old purlin into any new timber then I recommend piloting the old timber first.
You could try skew nailing with your nailer! One this way, one that way. I have an attachment for my drill, which I've only ever used for plasterboard screws, never considering whether I could use it for anything else!
My first choice would be to go with a thin piece of ply, bedded on foam with a lot of weight until set, but from the picture I'm not sure you have the room?