Had a couple of 1/2 sleeve Hartfords from the IS in mid '80's,(made in France in those days, dunno about later), lovely shirts,  also 4 from Russell St, I'm sure a couple had no labels in them and as I recall was told they were Hartford samples, one in particular was a lovely lightweight oxford , orange with blue/white check , and I also had one of those polo shirts , excellent polo, probably oiked it out as I'd gone off of the colour,
not sure if you knew this Runninggeez , the guy who owned Harringtons in Guildford, ( Ian...) was an ex IS guy, behind the curtain 1/2 way down the shop he had a copy of the (fairly) well known '60's photo of the IS guys (incl him),with John Lally wearing the sombrero, he knew I shopped at the IS in the heyday and always chatted, when Gant opened their own store in Guildford around 2010 it was the demise of his shop, he told me 50% of his business was Gant, he'd sold Gant from pre-logo days, I remember also 'Brooks' shirts he sold,(no connection with BBs), they were Italian, but very similar to the Hartfords,

I'd give a great deal to have that soft, comfortable shirt back in my wardrobe - supposing, of course, that it still fitted.

The jacket was a formal 2 button jacket in green with a centre vent.