If you're absolutely positive your placement/values/wire connections/vero tracks are all correct then that leaves the only thing you haven't checked.....the socket.
I've had at least one instance where a burr from a cut got trapped under an IC socket and bridged to another row. Took a few days to find that one! Use your DMM to check for any continuity where there shouldn't be.
What I would do now....using a DMM of course
With the board comp side up, check for continuity on all component legs on the same row. It will help find dry joints doing it this way rather than from the solder side.
Do the same with pot wires...from a component on the board to the lug on the pot.
Lift the 100n leg from Q4C row and measure DC on the collector.
Reluctantly remove everything from the tone pot 2 to the output and replace on at a time measuring at each stage.
.....and finally after all that.....set it on fire and nuke it from orbit!
But maybe just check the socket first