I've just looked back at a video I shot in 2016. That year the cones went from just after Whitegates to just after Waterworks 2. However, at the end of the cones and again just after the Gooseneck there were 50 signs. The first unrestricted sign came about 100 yards or so on from the Gooseneck.

Cones start again at the Graham memorial through to the junction at the Bungalow (but with no evidence of any speed limit signs).

Just after a 60 sign before Keppel Gate the cones re-start through to the Creg where the limit has just dropped to 40. The limit increased to 60 again just after the Creg then drops to 40 again on the approach to Hilberry. It became 30 just before signpost Corner.