It sounds to me like you found a Singer machine that's been put into a cabinet set up for a Japanese machine. Japanese machines used the dual outlet cord block set ups with a foot controller or a knee lever. Singer used a 3 pin junction on the machine, and on some machines had a separate spot to plug the controller(whether foot or knee operated) on the side of the machine. You could theoretically wire the Singer to work with the Japanese set up but it would be easier to find a Singer cabinet.
Cari