The Kodak processing labs have occasionally been known to cut and 'mount' V-M films as standard slides!
The instructions below are quoted from a letter dated May 2002 from the processing lab in Switzerland, which now handles all Kodachrome processing for Europe.
With regard to your request for "unmounted" stickers, I regret to inform you that these are not available anymore, as our Swiss laboratory has no equipment to print such labels. However, if you mention your request clearly on the customer's address label, or - should you send many films in one package - if you enclose a good visible note, we will leave your films unmounted.
May we also kindly remind you that we have an official code : one corner of the envelope cut means "slides requested in strips", two corners of the envelope cut is for "slides requested in an uncut roll".