Update: So I dropped the fan motor housing out, pressed the foam lugs in and checked the 'freeness' of the motor. To my surprise it spun ok without much friction - but I applied GT85 to both bearings to be on the safe side. It's all back together now awaiting the pollen filter / seal / new scuttle panel.

Whilst I was outside, I thought I'd inspect the existing scuttle panel to see if I could find where the water was getting in... er, it wasn't difficult, in fact I'm ashamed I never noticed a 10mm gap where it's come away!

Therefore I decided to order the replacement (redesigned) scuttle panel, pollen filter & seal. The cheapest genuine Ford parts I found was from a dealership on the south coast here: http://www.ebay.co.uk/itm/270665477080
£49 for genuine parts, inc delivery, can't really complain at that.





And - Hi Ian, good luck with your fix.
I'll mention now that you'll need to be dexterous and have a stumpy large crosshead/posidrive screwdriver to get the fan housing rear screw out, but it was straight forward.