Thanks every one for the help.. It's the fingers not the guitar that are the problem. At 75 years the skin becomes thinner. I will be putting the s&s strings on a Martin 00016 so the martin can take it.
Here is a list of the S&S strings on the market
Martin Marquis M1400
Martin M130
D'Angello 100 ss
D'addario
La bella
As to the thikness the Martins appear to be very slightly thinner
Any ideas on ones you may have tried?????
Thanks again.