And that was when in 1927 Rangers came in for him but at only nineteen as a reserve and that he remained until 1931-32, in the process converting to the middle of the half-back line. In part the time taken was because the incumbent centre-half had been until 1930-31 multiple Scottish international, David Meiklejohn, who then moved to right-half. In fact Simpson would seem on the face of it to have replaced Meiklejohn, eight years his senior, in the Rangers team and at pace from the 1934, so aged twenty-five, do much the same in the national team with a four cap interlude from the Queen's Park amateur, Robert Gillespie. Indeed, Meiklejohn would in the end finish with fifteen caps over eleven season to Simpson's fourteen over four. But that simple comparison hides considerable truths. Meiklejohn made almost five hundred starts for his club, scoring forty-two times, so a goal every eleven and half games, whilst for the country it was one in five. Simpson would make almost three hundred appearances for the club but his goals to games ratio was by then one in fifty-eight, whilst internationally he scored just once. For comparison for Gillespie for club it was one in six. 

And there were positional disparities too. Meiklejohn had been and remained a half-back, whilst Gillespie had proven himself also to be, as well as a free-kick expert, a good forward, indeed centre-forward. And whilst Simpson too had started in that same position perhaps most telling were the physical differences. Meiklejohn stood at five feet seven inches tall and weighed eleven stone. He was a solid specimen with a creative streak, who has stepped up the park. Gillespie was five feet eleven and a stone heavier, so a bit of a Dixie Dean, who had then stepped back into mid-field. Simpson, on the other hand, was six feet and much the same weight as the Queen's Park man, so tall and slender and, as is picture above shows a header of the ball. In short, whilst Meiklejohn and Gillespie were, albeit with their differences, "Scottish centre--halves" Simpson was not. He had evolved backwards into a centre-back and his selection for club then country marked more or less for good, although not without havering,  the abandonment, for which he carries no blame, by the club and national game in Scotland of the core that made it distinctively Scottish.

But back to the man himself. As he had waited at Ibrox for his opportunity he studied to be an engineer, the profession he took up full-time on his final retirement as a player in 1947, having accrued five League and four Cup wins, and latterly as a manager and from the game entirely in 1949. In the meantime in 1929 he had back in Dundee married Mabel Campbell and they were the following year to have their son, Ronnie, who went on to a twenty-four year career as goalkeeper both north and south of the border, notably at Newcastle, and also himself play for Scotland, including in a certain game in 1967. By then Jimmy had managed a bar in South Glasgow and he would pass away, recorded as a "Barman", aged sixty-three whilst living in Kings Park. His death was signed off by Ronnie, who was living in Edinburgh and that was where Mabel would die in 1984 at the age of seventy-five.