This is a model four Barcroft table lighter with a "Kretschmer Wheat germ" advertising logo, I happen to have had some of this when I was a child and remember it vividly.
From the outside the model four Barcroft looks exactly the same as the model three. The model four has a 'standard' Zippo lighter insert rather than the oversized insert of the model three. The body of the casing is hollow and filled with wadding, a raised pad where the insert meets the casing allows the Insert to draw fuel from the 'expansion tank'.
The model IV was produced between 1954 and 1979 and thanks to details on the insert I can narrow it down further to between 1959-1963. It has a 3 and the initials APC inside the lid (see pics).
Kretschmer are still trading so I have contacted them to aid dating it even closer, I will update this with any information they can provide.
The Barcroft takes it's name from Mr Blaisdell's wifes maiden name.