However, he had been signed as an inside-right and was not an instant success, loaned out to Clydebank for a season. And , in fact, it was there he was switched to centre-forward, being brought back and even then waiting a few months for his debut. That was in January 1923 and was again at first a slow burn with three starts before season-end. He only really began to show the following season, thirty goals in thirty-six games, leading to a Cup win in 1925, one of four, and the League in 1926, the first of two. 

And then came probably the turning-points in McGrory's career and perhaps in British football. First, in 1926-27 he scored more goals than he played games and would do so for the next six seasons and again in 1935-36. Second, at the end of the 1927-28 Arsenal tried to sign him and failed. Despite what would have been a £10,000, world-record transfer fee and Celtic wanting to take the money he simply refused to cooperate. For him it meant Celtic docked his pay for the next season. For Herbert Chapman it meant perhaps a failure to build a new team on his preferred Scottish model of small forwards an attacking centre-half and instead a turning to one based on big forwards and the centre-back.   

The reasons for the refusal of McGrory to go South are not obvious. His father had died in 1924 so he had no surviving parents. He was twenty-four at the time. He did not marry until 1931. But the result was that he never proved himself in the English game but then why did he need to. Scotland had, since The Great War, been Britain's top national team and whilst he had featured in it, the Wizards had just swept the English away at Wembley. 

When McGrory wed it was to also Glasgow-born Veronica Green but back in Donegal. It was to be the first of two marriages. In 1944 Veronica was to die at the age of just forty-five and in 1946 Jimmy remarried Barbara Schoning, this time in Glasgow. She was half-Dutch, half-Scots and probably born in Canada. They were to have three children.