I recently acquired what I think could be about as close to a "Bass of Doom" as you're going to find and need some advice on appraising it for insurance.
This bass was built by Kevin Kaufman (Jaco's tech/luthier) in the early to mid 90's as one of a few prototypes that he built prior to working for Fender when they manufactured their first run of 100 Jaco Tribute custom shop basses. Although it's almost 20 years old, it is in essentially mint condition and has not been "relic'd".
I have corresponded with Kevin who told me, "No it is not an exact replica...... the fingerboard is thicker because I extended the board to get the high E on the G string....... Jaco I think would have preferred that the board was slightly longer...... The control cluster is slightly larger too because so many people at that time were adding preamps to Hi Z pickup Instruments.... It was a practical thing at the time....... but it is roughly similar in weight and has the same epoxy on the board........
So while it's not an exact replica of the Bass of Doom, it's pretty darn close and was built by the person with the most intimate knowledge of the Bass of Doom (besides Jaco of course).
It has the Jaco sound, I had Bobby Vega, who is a real expert on vintage Jazz basses play it and and he could make it sing and said it was the real deal.
My gut feeling is that this bass has a value beyond the current Jaco basses being sold by the Fender custom shop which retail at $5800 USD, though street price is of course lower (about $4400). I realize the value of the bass is what someone is willing to pay for it, but would appreciate any input so I can make an honest attempt to value it for insurance purposes.