1992 would be the bigger mk2 crystal cover so your pump should be removable, if not and the pumps fixed then this is the mk1 and you will be hard pushed to get one.
Currently, the mk2 flap is readily available as the 'Truma Crystal' cover, if mk1 then best to convert to mk2 while stocks last.
Truma as far as I know are not making any more mk2's preferring to supply their latest offering instead.