To be honest - I've never jump started a Morgan. Push started both 3 and 4 wheelers though.
If you go the route of putting in cable for the purpose of jump starting, I suggest you do the job properly and terminate the cable in an Anderson connector. These are used by most of the single seat racers in hillclimbs and sprints where a starting battery is not carried.
http://www.demon-tweeks.co.uk/motorsport/battery-jack-plugs-anderson/anderson-jack-plugs
