Wiper wheelboxes

[Souwester]

This is allied to the wiper motor question, but different.
The wipers on my 1992 Cagiva Moke got slower and slower then stopped, I think the fuse has blown now.
I think all this was caused by the wiper wheelboxes seizing as the Moke had been in storage for some time before I got it.
The wipers are different from those in the manual but I would guess that releasing the single nut on each would be a start.
Does anyone know:-
1) can you remove the two dashboard trays and get at the wheelboxes that way or is it a 'speedo binacle out' job as well?
2) are the parts standard Mini ones or something different (Mini wheelboxes are under the bonnet Moke ones inside.)?
3) any tips worth knowing?

Thanks