In the good old days the City of Glasgow Police were never slow to stop folk from climbing the wall though I accept that even they could have done nothing to stop the Hibs invasion. They would, however, have intervened early and decisively and there might have been twenty or thirty in Court on the Monday. Unfair on the twenty or thirty, no doubt, but that sort of action discourages the others at a future event.
Break ins were comparatively rare and didn't impede the progress of the game the exception being a notorious match at Ibrox. Don't worry it wasn't the Rangers. Neutral venue for a Scottish Cup semi-final, celtic three - nil down to St Mirren fifteen minutes to go. One set of fans was disgruntled and invaded the field in big numbers and it wasn't Buddies upset bcause their goal tally wasn't big enough.
I can't rememberwhat punishment, if any, was given to celtic but as John Mc says, you couldn't expect the Kellys, the Whites and the Devlins to race on to the pitch to restrain their fans' exhuberance. They did the next best thing. They conceded the tie.
If that happened today, the host club would have been heavily fined, Ibrox removed from the venue list and a replay ordered at celtic park on the basis that a game at Hampden would give the winning team an advantage over the other finalist and other than cp no other ground would have been big enough.