It's not exactly t-shirt weather right now, but if you happen to be going somewhere warmer (or the house is warm), you might like this Tokyo 1964 t-shirt at Gama Clothing.
It's part of the retailer's Gary Crowley range, although he quite obviously didn't design this – the logo for Tokyo 1964 was the work of Modernist designer Yusaku Kamekura. But the use of the Olympic rings does have a 'mod' connection – Marriott was famously photographed in s sweater featuring them.
It's a slightly thinner 160gsm t-shirt, with an 'American college cut' and double stitched hems, available in all sizes. All priced the same – £20 each.