I'm only starting out on researching my name and so apologise if I'm telling you something you already know but I've seen Tough spelt as Touch quite often (also Towe as in Alicia la Towe 1275)- the name comes from the Gaelic word 'Tulach' meaning a hill or knoll and I guess the -ch develops (or developed)into Touch. Just to confuse more - there was a person called Isabel Toulch, sister to Henry Toulch of the lands of Toulch in the Sheriffdom of Abirdane. I've even seen a Sir James Toucht who was a notary in Fife, 1549, and Thomas Toucht who was keeper of the inner dood of Exchequer in 1561.Whether they had bad eyesight and/or lighting (!) the name obviously appears to mutate or develope through the years. Whether this was caused by a slip of the pen or an aid to pronunciation I don't know. I hope this is relevant and is of some help.