Can't help with the clocks but cleaning....that's kinda my thing.
There are many roof cleaning products to use but the better ones have two products, a cleaner/conditioner and a reproofer.
The cleaner is obviously used first but you need to apply it liberally if it's really dirty and rub it in with a soft cloth. It'll product a green foam which can be rinsed off, dabbed dry and repeated.
Once the worst of it is off you do it again but this time use a soft nail brush. It's really good for getting stubborn marks from the edges. If you need to you can partially lower the roof to get better access. The brush also agitates the mohair so if you work over any shiny areas where the roof folds when down it can bring them back. Just be careful to blend in where you use the brush or you can see you've used it and where you haven't when the roof is dry.
As for the proofing, use as directed but generally it's a case of spraying on and dabbing of the excess with a clean cloth. Any overspray on glass, paint or rubber will not cause issues as long as you clean it off straight away i.e before it drys.
If you're thinking of using a product to stain the roof dark again be very careful to get one that's intended for your roof. I've seen a roof ruined but using a product not suited to mohair to the extent it looked so bad it had to be replaced. Personally I think a good clean and proofing restores a roof well enough not to need anything else.
Happy zedding.
from me in South Yorkshire .Glad you have joined and maybe see you tomorrow 
