These were usually school or club blazers, more often the latter. The stripes are either all equally sized and broad (the awning look that Formby refers to) or narrower stripes of around 1/2 inch broadly spaced. The former are usually club and the later can be either club or school. The cut is normally patch pocket often with the badge on the breast pocket and plastic or horn buttons. Sometimes brassy metal buttons are used with the club crest on them.

A school's Old Boy association may have a similar blazer although these have often been discontinued over the years, in the case of my old school it was ended in the 1930's. In that case it was a regatta style in the school colours with horn buttons. At one school we had straw boaters for smart dress - small boys can destroy these at an alarming rate.

My feeling is that these blazers are bordering on costume outside their intended setting but that said in the right setting or with the right attitude it can be happily pulled off. In England they have the same limitations as striped ties although I suspect people would be less upset provided you did not use the club badge.

Thanks for the information. the trailer really looks like BSG.