I think Bank of England have the right to stop the sale because they have the copyright for the banknotes even if the Novelty tissue doesn't look like real money. They don't said anything about the action that Bank of England will be taken against the shop. I think they're also many same story to Malaysia banknotes too but most of it doesn't come out to our national newspaper. The recent one is an engine oil company who produce a discount coupon that look like a RM50 banknotes. The coupon has been withdrawn by the company but many collectors that I know still like to keep the coupon.
You are not allowed to reproduce the Malaysian currency. It is also illegal for you to use any photograph, drawing or design of any note, coin or any part of the note or coin, of any size, scale or colour, in any advertising or on any merchandise or products, which are manufactured, sold, circulated or distributed except with the permission of BNM. You may be ﬁned up to RM5,000 if you were to reproduce the Malaysian currency without the permission of BNM.