Who doesn't remember John Noakes going up Nelson's Column? And the camera man, who apparently had to do it twice!Those clips remind me of the means of access to the roof of St Michael's Abbey, Farnborough. Hoop irons, built into the outside of one of the stone buttresses - no safety cage or anything like that. From the first roof you could walk along, climb a short ladder to the raised roof under the dome, walk up some lead covered steps at the end of the roof abutting the base of the dome, and then get to the ridge, from where we had to provide scaffold access for an architect to clamber into the lantern to find out why water was dripping onto the congregation.
Spectacular view of the Surrey and Hampshire countrysides (Surrey to the north, Hampshire to the south) while sitting on the ridge as the scaffolding company's manager measured up to price the job
While that was post-1974, the safety elves are much more active and you wouldn't be able to do it now