Its all about time to me Jon I've not used cement and bricks before :embarassed: if it was on ground level I would have a go, but the cost of scafolding these days its not cheap rather have someone just take out the bad courses and cap it over.
The fire place is not being used plus if I wanted full tile replacement it would mean more money and noone can see that side of the house.
Anyone near who can do such a job? the scafolding will be inplace before anyone comes I need to plan it now or come winter I fear the worst TBH. 
If you're not using the chimney, then cap it with a paving slab. Just take the bricks down to the level of the flashing, and the other crap ones below on the other side. Salvage the good ones to build back to the height of the flashing, then lay the paving slab on top.
Get a pointing chisel or use an old heavy duty screw driver to get the old cement out the smaller vertical sections, then finish off the repointing with a cement that's not as wet as when laying bricks. You won't be able to force a wet cement inbetween the bricks, as it will slop out and make a right feckin mess.
It's best to clean out the old cement (below the flashing height) that you want to repoint while the chimney is up, as the weight will hold the bricks nice and tight.
