Molex plugs are pretty standard, and available from many
different sources. You need to measure the pin spacing
and pay attention to the keying tabs on the plastic housing.
In one case, for the plug on the back of a TS-450, I had to
shave off a couple of the tabs with a pocket knife to make
a standard plug fit, but it has worked for 10+ years now.
The specific Kenwood plugs for the transceiver end are
available from a number of sources, but I don't know
about the plugs for the power supply end: I checked
my Kenwood power supply, but it had been converted
to an Anderson connector before I acquired it.
But, unless it is an unusual type, I'd probably check
the major suppliers like Mouser or DigiKey and you
should find something that will work.