On your previous writing:
The transistors are socketed but the chip is not. So it's not practical toLook carefully... it's more likely it's socketed than not.
Tek used a lot a kind of socket that is made of individual socket pins that go directly on the board... (on really wide PCB holes),
To bare eyes, it's very easy to overlook it.
When I was still new to my 464 I also thought they were soldered.