The problem with bands like The Rollers, Bros, etc. is that their appeal was completely rooted in pre-teenage and early teenage girls.
Unlike Take That and similar, whose appeal can be brought in line with the age of their original fans, the Rollers are caught in a time-warp and are unable to make that transition.
If they rock up in their tartan outfits, being the age that they are, and lets be honest, some have not aged well, they are going to look like an end-of-the-pier parody of themselves, and they will only attract drunken hen parties who intend to point and hoot.
It's not edifying, and money or not, they should maintain their dignity and leave well alone.