Thanks for the DB reminder.
That Agfa back got epoxied to a 4x5 holder so I can use a darkslide. The ground glass spacer had to be 1.697", however! A friendly machinist (I'll call him 'Chip' to protect his identity) insisted on 'hogging it out' of a solid block of aluminum instead of 4 separate sides.
The back of that beast is done but I'm still messing with the front.