I do know there are some articles the publication of which are planned to coincide with this centenary. & Don't forget the NT were actually on the side of the public back in 1901-5 !
To get back to the management, however, I would draw your attention to the fact there was a Stonehenge custodian prior to the 20th Cent, which in itself suggests management prior to the erection of the fence. Hen Brown appointed himself custodian, but the owner Antrobus did have a paid custodian in place at the end of the century as curiously he was off sick the whole week prior to the new century when rather miraculously a trilith fell on the stroke of midnight and provided both 'Act of God' and hazard that justified fencing off and charging for entrance in 1901. The locals held a protest march, and very impressive it was too, but the management of the site had been a problem to Antrobus who really wanted to sell it to the govt but they couldn't justify the price he wanted.
I can't remember why I went in to all that, but I feel better now.
VBB