Although The Wombles would have been at the height of their popularity during the film's mid-70s setting, the appearances of the featured Wombles are based on the designs from their late-90s revival, in particular Wellington. Also, Alderney is shown - although included in the books, she didn't make her screen debut until the 90s series.
The colour of the foil tops on the milk bottles changes colour between shots. They are silver when they're outside on the doorsteps with the robins picking at them and when the housekeeper picks them up to bring them in. When she puts them on the breakfast table inside in the next shot, they are golden.