BJ’S only (known) surviving 1906 Waterman Porto is rare,
was commercially produced, and has considerable value.
Its not for sale so you can only speculate what its worth.
Any 1 of 1 motors out there the would just as rare, they
could be worth more or less. There is not really any answer
to these types of questions because even though your
asking for the one and only the examples that fit have
variables (like value) that aren’t clearly defined.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.