I believe from models around 2014/2015 and possibly later.
Attached to the top ‘flat’ black sections go two small upright metal box section fittings. I do not have these* or the bolts/screws but they are available on Amazon for £14.69 and £16.99 - search Sony Stand Neck - see screen shots.
*but have photographed what they look like as I have the same ones on my new (to me) 50” Sony TV and the 42” Sony TV I have for sale at £75.
Collection from Peterborough PE3 welcome - otherwise will be posted.