Martin, thanks for the comprehensive reply with your thoughts on what the causes of the lumpy steering might be.
All joints are phased correctly on each shaft as far as I can see although I've not checked the one you mentioned behind the steering wheel yet. Nothing is loose, there is no chassis or crosshead damage. As for the position of the steering rack, I'm not sure, all I know is I carried out a lot of research prior to buying the car including contacting the well respected dealer who sold and serviced it for the first couple of years. I was assured by the dealer I bought from that it had never been involved in any accident and after purchasing it I put it to my "local" Morgan dealer who serviced it and also gave it a clean bill of health. I have quite a keen eye for detail and nothing looks out of line, I wouldn't have bought it if it did.😁
I spent a couple of hours last night trying different uj positions and sliding the shafts to different positions on the splines. I've got the steering to a point where the inner wing at the bearing mount point no longer visibly moves, but you can feel a tiny degree of movement if you place a hand on it. This was achieved by setting the ujs to a similar position as described by Richard. I would say the relationship between the top and bottom bolt is around 35/40° clockwise in my case and it's definitely an improvement on before. When turning the steering on axle stands it's fairly smooth but you can definitely still feel the regular pulsing resistance when turning the steering from the wheels.
I'll live with it for now until I get the chance to check another car with a similar steering layout to mine, then I'll be in a better position to judge if there is an issue that needs more investigation.
Many thanks to all who took the time to reply.👍
