The dead fan is a 60mm. I don't have any spare 60mm fans. But I do have an 60mm to 80mm adapter. Long story short my CPU is now being cooled by a 80mm Cooler Master fan which is glowing red thanks to 4 LEDs... This looks a little alarming as the heatsink is also glowing red.
In a frantic search for some bolts to put this together I remembered there was a tool box, amongst my dad's belongings, full of Meccano. I quick look through the box and I found 4 of the longest bolts but they looked to be just a little to short. However as luck would have it ... they self tapped into the plastic adapter perfectly.
Now I need to order a new adapter so I can still do the air flow test on various fans, I think I will order a blue LED fan as well it's very disconcerting looking into the case and seeing the heatsink looking as if it's going into meltdown... but at least I have a working PC again.
Plan for the next few hours... Have a coffee, call building Society, then move boxes to get at the last of the boxes that need cataloguing.