I have not had a look at the construction of the diff but in days of old we used to put a trolly jack under the diff on a Holden to jack up the rear. Is that not possible with a Morgan?
I think the question was more about where to locate the Axle Stands. (sounds obvious

)
I find it best to put the trollie under the rear chassis corners and put a stand along side if I dont want to lift the axle for chain spraying the rear springs.