Does anyone have any idea where I might find something that fits? The requirement is 105-120 volts, 60 cycles, 95 watts which should be pretty standard but it is also the connection that is troublesome.
If the prongs spacing is standard then It does look like an extension cord will fit. Easy enough to try before you connect the other end to the wall outlet.
The tape recorder doesn't need a heavy cord. Anything you use will be fine.
If the machine hasn't been powered up and used for a while be prepared for it not to work. There are a lot of rubber bits that are perished, capacitors and resistors no longer meeting their specs and maybe tubes that need replacement. It would be a project with a long learning curve.