This is a 1961 Strat, serial-no. 68354, with rosewood  fingerboard. The left picture is from the beginning of the 90ies, note the damaged laquer. When Mark bought this guitar it had a natural wood finish, but he soon had it repainted in red. With this guitar he fulfilled his dream of a red Strat, the guitar his childhood-hero Hank Marvin played.

In the seventies Mark had a DiMarzio pick-up in the neck position. BAsing on all information about DiMarzio's product range back then, it can only be the Fat Strat (FS-1, DP 110)

He still has this guitar and uses it occasionally. 

related articles from my blog:
Early Dire Straits: Which of the two red Fenders was used in which concert?
Pictures from Hamburg Oct. 28, 1978 (?)

Backstage in Essen, Germany, Nov. 1979 (left to right):

David's black Tele, Mark's 80470 Strat, David's black Strat, Mark's sunburst Tele Custom, Mark's Les Paul Special, John's Precision Bass, another Precision, Mark's 68354 Strat