When thinking of “vintage dancing girls” your first thought might be of maypole dancers, such as the ones shown above. Although images of girls dancing around maypoles are common there’s no tradition that confines it to girls alone, You can find plenty of examples of boys and girls maypole dancing and, indeed, adults of both sexes.
Often maypole dancing goes alongside other traditions such as choosing a May Queen and would be part of much wider celebrations with many onlookers.
Postcards of maypole dancers tend to be more collectable and therefore more expensive to buy than other cards, especially if the location and date are given. Topographical RPPCs are probably more popular than any other kind and it seems natural that if you collect scenes from a particular town then you will want to have non-topographical materials from the same area. (Similarly cards showing floods or natural disasters from named towns are even more collectable and more expensive).
The wikipedia entry for maypole gives extensive details of the likely origins and appearance in other countries and traditions. Perhaps surprisingly the general conclusion is that the maypole is not phallic despite the explanation to the contrary given in The Wicker Man film and the popular imagination.
There are many other traditional “folk” dances to be discovered. This pipe dance is similar to Scottish sword dancing. The idea is that the dancers must avoid breaking the pipes as they dance around them.
The garland dance was apparently introduced by mill owners in the 19th century. In this case the wikipedia entry is light on detail though garland dancing can often be seen at folk festivals right up to the present day.
Then there’s clog dancing practiced throughout the North of England and Wales as well as being exported to the USA.
I will leave the consideration of female morris dancers for another post even though there are those that maintain it’s purely a male pursuit. (I’m not one of them).