Aguilar OBP-2. I cant imagine you would want to add MIDS to a P, so a boost/cut in bass/treble might be what the doctor ordered.
The OBP-2 is small, easy to install, can be used in a stacked knob (no new holes). The tricky part, 9v's don't fit well in P Cavities, and removing the pickguard to change batteries will get old.
Solution, go outboard.
"But lay up for yourselves treasures in heaven, where neither moth nor rust doth corrupt, and where thieves do not break through nor steal:" Matthew 6:20