Ah, but mine is not a "Saturn" it is made by Tinsley Laboratories, Berkley, Ca. and badged as a "Commander".
The plot thickens...
"Come, Watson, come! The game is afoot. Not a word! Into your clothes and come!"
- Sir Arthur Ignatius Conan Doyle
Had a little time to investigate the Tinsley spotter today. I removed the focuser and checked out the lens assembly. The aluminum lens shade is cemented inside the main tube and the lens cell is mounted into that.
It looks like the cell unscrews but I can't see how as there are no notches for a spanner on either side of the lens that I can see and the lens is recessed into the shade/cell. I didn't try to disassemble any further. I saw no other markings anywhere on or in the scope.
The tube has definitely been repainted at some point (not great) as there was white over-spray inside the tube with a lot of dust particles and fuzz. Now I was hoping that the the "dust" on the inside of the lens wasn't paint particles.
Since I couldn't remove the lens I attached a soft lens brush to a wooden spoon handle with a rubber band and gently brushed the inside of the lens while holding the tube up. I checked the lens under the light and was pleased to see most of the dust came off - no scratches either! Then I used some Zeiss wipes to clean the front of the lens and the ep/prism.
After a good look under the light and a nice cleanup I could see some purplish hues so I guess it was coated and they are still intact.
I also had some suspicions about the diameter of the lens as I was tinkering with a 50mm finder on the workbench and compared the two side by side. The spotter was definitely larger so I grabbed the digital calipers and measured the lens as best I could inside the cell and came up with 55mm. Odd.