In reply to Gordon Stainforth:
> (In reply to Chris Harris)
>
> I'm surprised that people are so baffled by this. It really isn't a problem for the simple reason that 'Paint Trophy' becomes a compound noun, similar to that used in newspaper headlines every single day. The people to whom the paint trophy pertains are called Johnstone, so here the possessive remains Johnstone's.
That is what I said.
>
> In the present day and age, one can even imagine some people wanting to drop that single apostrophe, just as Waterstones have with their bookshops. It would then be a triple compound noun/name, 'Johnstones Paint Trophy'
Are you sure that Waterstone's have done that? How recently did that change? The change in signage may not have reached my branch. I have met some of the Waterstone family and perhaps the ownership has spread across them so that "Waterstone's" is less accurate than "Waterstones'" by which point I would not blame anyone for dropping that final apostrophe / quotation mark