I have finally posted a shot of the production chassis underside, primarily so you can see the impedance switching boards that mount over (under) the output transformers.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.bottlehead.com%2Fsc_images%2Ffinishedweb.jpg&hash=6c77e8fabccff3106de1fbf42f5143df07829d6c)
