David,
Most of us would not dream of specifying PS on a trad Morgan.
The 4/4 especially is very light and nimble and you will probably find that it is not necessary.
If you do feel that you want to make things even easier , then get someone like "Spanner Juggler" to fit a Peter Mulberry bearing with new front main springs and ensue that your front suspension is greased properly. That will make a difference, and I would be most surprised if want it any lighter than that.