£1441 to LAS for the same period- less TPs but J flights to LAS which go from (or from near) London seem to be typically pricey, seems to allow pretty generous routings via most US cities for the same price.
(i.e. less of a mileage run and more of just a decent deal?)
Also, the trip across town on the return helps with the inevitable meetings I end up needing to get to between LHR and LCY.
Edit: When going to book though, pricing seems to jump by nearly £1k...
Edit2: helps if I read to the end where you talk about the OTAs. Apologies. It's Monday...