Jackall Ram Seals.
These are the inserts needed for each of the four hydraulic jacks on the front and rear wheels. They have been reproduced by copying an original seal and should give a more relisble seal than some other modern replacements which appear to rely on a smaller contact area. Taking the jacks apart and renewing the seal is not the easiest of tasks, but some good advice can be found on this website here - http://www.mgccyregister.co.uk/technical-information/servicing-2/jackall-repairs/
Don't forget that the Shop also sells the jack top fittings and other tube nuts and olives needed to make your system function as it should. Just look for the word Jackall on the items listed in the Resoration Items section, but please note that the latest additions are at the top of the list alphabetically, but items which have been on sale longer appear alphabetically further down the list.