I've submitted a NOTAM proposal to NATS - not sure if they'll do anything with it. Yeah Stokenchurch mast is still there and makes a good reference for crossing the Benson MATZ going West and the Chilterns going East. Just 4nm SW of Didcot there is also the Round DIAMOND light source building at Harwell - not so visible but very distinguishable (but keep above it at least 2500 ft radius 2nm).