A large, old cash register fascinated visitors, some of whom could remember the time when they were used.
Museum volunteer Joan Stevens, one of 20 helping out, said the cash register had come from Alexandra.
It was similar to the one her father, Robert Hewitt, had in his large general drapery and newspaper shop in Alexandra from 1920 to 1978.
Then it went to Olivers Bar and Restaurant at Clyde.
"The notes were placed at the back and the coins in the front compartments.
"The price of the goods purchased only showed up on the assistant's side, so the customer could not see how much was being charged.
But the government made them change it in the 1970s so the customer could see the price, as well," Mrs Stevens said.
Museum director Brian Patrick said the huge interest in the open day was heartening, and there had been people coming back yesterday wanting to learn more.
He had expected that the museum would be quiet during the winter, but that had not happened and interest from local people and visitors was increasing.
"It's definitely becoming a year-round activity and we are getting busier all the time," he said.
