Frother bars were on the front of the sweets for kids display in my grandparents shop in 1966 in Bradford-on-Avon.
As a treat I was taken, when very young to watch the making of orange and lemon wedge-shaped boiled sweets. They were made in huge copper bowls in an oven then poured over a table full of little crescent indentations, rolled viciously then cooled.
They were broken up before our eyes ready for eating and they tasted magic!
Where I live in France there is a junk-antique shop that has a mould similar to those in Melksham but unfortunately it’s not for sale!
Keep up the good work,