Thanks folks, my minor injury is making it rather awkward to clean any more knives, but this simple friction folder doesn't really need any cleaning. It's a traditional penny knife from Austria, which like others here, I was first introduced to by our old friend Andi
@Humppa 
It is called a Trattenbacher Taschenfeitel, and it is manufactured by Johann Löschenkohl.
There's an interesting article about the history of the pattern on
Wikipedia (this is the English translation which has a number of shortcomings), which includes details of the Austrian version of 'mumblety-peg'