I posted a thread a couple of months ago about fretless redos and here is the follow-up. I sent my Sonus 5 back to Joe and company in California to have them do a fretless conversion. He charged $450 and it took longer than he had said but oh the results! First, I asked him to use darker more subtle lines than the usual lined fretboard, something to guide me but look fretless. They are perfect, subtle, but a nice guide for the player. Next, he put a satin finish on the neck, a really nice touch and so smooth to play it's hard to describe. Like greased graphite. The tone is perfect. A nice swell/mwah and with the bridge pickup soloed and an NE-1 in the signal chain it is THE fretless sound I have been looking/listening for. Just for reference mine is a J/J with Bartolinis and 2-band EQ. If any of you are considering a fretless redo on your ZON, go for it. It may take 6-8 weeks but Joe will send you back the bass of your dreams. Oh, and he also sent it back to me in a brand new Zon gigbag (mine was pretty sad). Thanks Joe!