Update:
Don't refer to the Highways Agency PDF maps online - they are wrong - according to SCC not ME!!
Gibbett Hill / High Button / 503 (you choose your name preference) is still TRO - as we know already. Don't go near it!
Summary from SCC:
They are all open with the exception of Byway 503 known as High Button, which runs north east to Roundels Cottages.
Byway 500 is open and should be used with care as it gets multiple users. The old A3 is having a layer of top soil and other landscape workings on it, and will no longer be in use.
If you drive down 500, you will be able to cross the old A3 (this section is open for those crossing) and use either 500 or 501 past the youth hostel.
There you go.....be good and obey the law and green lane conduct so the rest don't get a TRO!
Happy days...