Um, it's a bit too late now, but did you consider this Big Band period-accurate -
and non-invasive - option:
https://shop.guildguitars.com/produc...-mount-pickup/
IMO Epiphone should have done something like this from the get-go - I also think a piezo bridge is a bad idea on a guitar of this type - and I'm hoping they get it right on the long-rumored/long-awaited successor lineup...