I have a MIJ Jaco Jazz and have had the neck epoxy'd.
I have NJ4SE pickups and an Audere Pre-amp. Otherwise it's stock!!!! : )
Anyways, I'm still getting a slight phased sound from this set-up, which I don't like and I really only ever use the bridge pickup so my Audere is a bit overkill (I wanted a blend).
I want the purest Jaco tone possible, I'm thinking of ditching the Audere going back to passive and installing NJ4s or SD Antiquity IIs. I hear hand-wound and overwound give the best antique sounding PUs plus there's loads of boutique pickup makers out there and it's difficult to choose. I don't mind trying a few.