As i read it your Morgan was made and first used in 1992 - there was a "transition" period 1/8/92-1/8/95 where by cars didn't have to have cats and the like fitted.( advanced emission control systems) Such vehicles should be subjected to a non-cat test. Its explained in the introduction section of the in service emission standards - its a bit hard to follow granted and confuses a lot of testers let alone car owners.
This hasn't changed in the 19th edition - its the same as now. So please don't be concerned - the MOT scheme isn't out to make lifes pleasures more awkward.
