The issue was what I expected - there is a washer/gasket where the prop shaft spline connects into the rear of the gearbox and there was a slight issue with this part which led to the fluid weeping out the back of the gearbox. Apparently there can be a number of reasons this part has this problem, but in most cases it's linked back to a manufacturing defect according to Dean.
I thought it'd be an engine out job as it's extremely difficult to get the propshaft out due to the prop shaft guard, but Dean said they take the diff and propshaft out and got access to the rear of the gearbox from the rear.
The part has been replaced, the car was taken for a reasonable test drive and then was left stationary over the weekend to see if any fluid was weeping (again) out of the back of the box... No fluid now present, the box was totally dry.
So Dean suggested I could get the car back on Wednesday (yesterday) which was much earlier than expected.
|Keith from Caterham delivering my car back post gearbox fluid weep fix.
|Propshaft in gearbox with no leaking fluids.
|My new blatting glasses - custom Oakley Racing Jackets
|iPhone 6 fits just perfect in Caterham transmission tunnel top.
|Whereas the iPhone 6 plus is just a bit too big.