That is neat!
I did not know that Domestic made this model under their own name. They made the Franklin for Sears, as Sears required a machine that looked like Singer -which is why the Singer plate fits (as will the shuttle and needles). The exception is the belt being on the outside of the flywheel.
You should be able to find manuals and info under the Franklin badge - Sears sold a lot of them.
Make sure to ID the machine in any manual - as Sears used the name "Franklin" for more than one model machine.