I've just had a load of racks from Alec delivered for my CPCs, my cash set from last year fit fine, my tourney set will be here in a week or so once it clears customs, I'll let you know if there are any nasty surprises, I just went ahead and ordered, so I hope I don't regret it!
My cash set was all pretty much 67.4mm, except for my £25s which were 67.0mm.
You'll prob be fine with 67.5mm (which is what I went for) but 67.7mm would be more than safe, same dims as the Key West racks. Will confirm though...