You can order a custom version of pretty much any model of 500/1 and 500/2 series that you want. If you do, the factory sends the bass unfinished unassembled along with all its hardware to a gentleman in Chicago (their USA Custom Shop) to make the modifications, finish and assemble the instrument. It's then sent to the dealer for delivery to the customer.
In addition and more recently, the factory itself has been doing more of the custom work now that they have more production time available to them. That's due to the Chinese made CT Series taking production away from Germany which allows them to focus on their regular production and custom configured/finished instruments.