I am usually not the "do a search" kinda guy, but in this case, it would get you to a lot of exactly the info you are asking for, so I'm providing you a few of the links that came up when I did a quick search.
Additionally, I will add that I had a Devon Diamond J5 that I got from Mr. Majestic. He is a very knowledgeable source when it comes to Devon basses. I really liked the bass and only sold it because I had more 5-string basses than I could play in active rotation. Excellent build quality, nice preamp and pickups, excellent tone. What's not to like?
Devon J5
Devon J5 fretless bass
Bass Mods vs. Marusczyck vs. Bacchus vs. Devon J-style bass
Custom build recommendation for new 5er -- my new DEVON bass!
The Devon I used to own is pictured in this group.