Regarding the descent paths from GDP to station Entry Point to overhead, a question about Gee on another thread prompted a memory. Prior to 1964 the bombers were equipped with Gee 3. Given the local range of Gee it was SOP to switch it off at TOC and back on at TOD.
This is where the EP to overhead came in. The descent track was aligned with a Gee lattice line that enabled very accurate navigation to the overhead and a correspondingly small safety height area. Cross track lines gave accurate distance to go enabling a very accurate descent profile.
Gee was replaced with Tacan in 1964 and I think I only every flew in a Gee equipped Vulcan on one or two trips. Our 'guest' plotter on the OCU (Wg Cdr King) said it wasn't a proper without Gee.