At the moment, I do not have a lot on information on this machine. The predecessor for Brother Knit model 43, Brother KH35, was manufactured and first sold in 1955. Thus, Brother Knit 43 was very likely released to the market in the late 1950s.

It looks like a standard-gauge knitting machine with 184 needles (judging by the needle count strip in the pictures).

Despite lack of information on the Brother Knit model 43 machine, there is a manual online for the Brother KH35 model, which looks very-very similar to the Brother 43: carriage has the same dials and buttons, the carriage handle has the same style an curves, the (un)foldable end caps/extension tracks, same number of needles, etc.

Thus, read an article on Brother KH35 in another post, while I find out more on the Brother 43 machine.