Meynell Vitesse not working

Thanks Barrie, much appreciated. I got the front cover off using brute force as the previous owner had rammed the knob on with the key over the splines. I cleaned the cylindrical filters in what I think you'd call the manifold - there was a lot of plastic shavings typical of someone not cleaning the tank after they'd drilled. I also freed up a sticking brush on the motor - it's been working but has now stopped again, same problem, noisy and zero flow. The shower head and hose are new and clear. Are there other filters which I can access? If there is a filter on the inlet (where the 15mm copper meets the manifold) then I guess it's full of the same crap that was on the cylindrical filter but I am wary of dismantling that far. I have tried to get a plumber but no-one available until after XMAS! I'm at the point of sh1t or bust as I have no shower and no plumber so, I'd be grateful if you could tell me the best way to approach getting the contraption apart to access the inlet filters - if there are any! I guess I'll have to loosen most components off until I can release the pipes from the inlet (???). I've tried to attach a photo for your perusal. Any help gratefully appreciated.

Many thanks.