First you want to test each driver that it
A, hasn't failed to a open circuit by putting multimeter on DCR ohms. Should measure somewhere from 3 to 14 ohms. Less than 3 I would suspect failed short circuit which would explain the amp going poof.
B, still makes a thump with 9v battery.
The DCR measure is a little less than the nominal impedance for the driver.
That will inform the choice of wring scheme.
Given your substitute amp has way far more power than you need it might not be a bad idea to go high on the cab impedance wiring, to cut down on risk of blowing it up.
Eg 4x16 ohm can be 16 as a series parallel instead of 4 ohm parallel.
4x4ohm can be 16 all in series instead of 4 series parallel.
Your pjb box may have had the amp taking up some internal volume? Probably not enough to upset the tuning if you block it off nice and good.