The M&S Archive twitter account is a great source of inspiration and one you should definitely follow if you don't already (@MandSHeritage). I wish M&S still made clothes like this now, the St Michael range produced some great clothes in the 1960s and 1970s. Introduced in 1928 the name was adopted as a 'quality guarantee' and appeared as the St Michael Quality Promise on the back of food products, on the side of delivery vehicles and on in-store ordering receipts. The brand was sadly discontinued in 2000 but you can still find good examples of St Michael clothes on ebay and in charity shops if you're willing to put in the time. I have a few pieces myself!