Using the code supplied by your amazing memory, I have just found that South Lakeland Minis also have them, but for £1.65 as opposed to Rimmer's £2.82
I want to order four to be safe, so SLM is £6.60 (£10.10 inc P&P) as opposed to Rimmer's £11.28. Can't find out how much their P&P is without going most of the way through the order process, but even if it's free, SLM is still going to be cheaper!