Included with my recent dob purchase was what the previous owner described as a 100mm finder.
The objective show it as being made by Leitz Wetzler Germany and also says EPIS 1:4 / 400mm. He described it as a refractor when I spoke to him in person and he had fitted a brass extension to enable EPs or a diagonal to be fitted. Interestingly it focuses by turning the objective.
Excellent. Thanks Matt! Apparently is works perfectly OK a very basic scope, at least good enough for being a large finder, though it is a bit heavy. I will see if I can figure out a way to mount it.