1. "what is the tube diameter?"
26 mm = 1.02", slightly bigger than 1".
2. "where is the Paralax adjustment ? All I see is an elevation adjustment."
the focusing adjustment is the small "wing nut" on top of the elevation turret.
3. "if this is a typical claw mount, the rings are soldered to the tube and are not easily removed. If they are the tube needs to be "desoldered" and re-blued. (total disassembly). Are yours not soldered on ?"
disassembly is relatively easy with these old Zeiss scopes, did it several times, f.i. for Xausa. Ocular bell and objective lens are screwed off, as is the elevation/focusing adjustment turret. Then the complete innards, mounted into a seperate inner tube, are slipped out to the rear. This may be difficult here, as the dent may bind the inner tube.After removing the inner tube assembly, the dent in the outer tube may be removed, just as you remove a dent in a shotgun barrel.
"It must have had an interesting mount on the drilling as the scope has no windage adjustments"
German mounts usually had windage adjustment via opposing screws built in. But sometimes windage adjustment was by drifting the front claw mount base in it's dovetail only.