Homebrew PCBs

Hmmm... I wonder...

pre-drill the via holes (or all of them I suppose) to match some wire
you have.  Push wire through and clip, so that it sticks out a little on
each end (as little as possible, or just re-trim them after the plating
step).

Now use a plain copper plating bath to fuse the wires to the copper
clad.

grind/lap any copper sticking out to re-smooth the clad for etching.

If one were clever, one could "float" the pcb on the plating bath, so
that it only plates around the vias and not the whole copper surface.
You'd have to do both sides though.  Or only put anodes to one side of
the pcb, and electrically connect the other side.