I suspect it has some provenance, which will help its value..
but hoping the value is higher that a Vincent, a boardtracker twin, or an early EL knuck..... is just comforming the owner has no clue..
I mean if its an even 1000cc Excelsior...it would do what 72mph...
Sure its unique... but that dont equate to priceless.. Probably has tried to sell it to Leno, and got shot down in flames...