I have checked MSDN and there seems to be no unique ID (UUID or whatnot) property in the Presentation
object model ( https://msdn.microsoft.com/EN-US/library/office/ff746640(v=office.15).aspx )
According to the code example, a Presentation can only be identified by a name only. e.g.
Presentations("Sample Presentation").Slides.Add 1, 1
Is there anyway I can identify a presentation by way of an ID? Hopefully it will looks something like this
Presentations("067e6162-3b6f-4abc-a171-2470b63dff00").Slides.Add 1, 1