"Drake already did that. They took a TR-4CW, converted it to all solid state
and repalced the PTO with a synthesizer. Called it the TR-5. Nice rig, but
they only sold around 1500 of them"

Nope I have a TR-5. It has an analog vfo. There is a separate
synthesizer for the TR-5, but it made of unobtanium and priced accordingly.

The TR-5 came out after the TR-7 with the intent of being a poor man's TR-7.
But, it was priced the same as the Japanese rigs with a synthesizer and many
more bells and whistles.

The TR-5 is really closer to a solid state KWM-2 than a solid state TR-4.
it is one of those perfect for your deserted island, where you cannot get
parts.

Colin K7FM