Your scope looks like either a Tasco 7T or a Space Scope, but probably the former, as I don't recall seeing any Space Scopes with metal knobs. The maker was Astro Optical Ind. Co. The serial number on the lens cell doesn't seem to have any direct correlation to the actual age of the scope except in general terms. I have three of these scopes - one Astro Optical #11925, a Tasco 7T #22318 which I can reliably date to September 9, 1957, and a Space Scope. From the look of your scope, I'd guess it's from 1959, possibly 1958. In any case, it's a fine scope and you will enjoy the views.
Hello MikeRam and Charlie, I had seen you scope on CL and had asked the seller to send me a photo of what turned out to be the missing ID tag on the focuser. My initial guess was a Space Scope Research Optical 60mm x 910mm. But there are other brands of imported scopes from Japan during this time period that look very similar to the Space Scope models, for example, Peer Scope is one that comes to mind.
After looking over my documentation for the early Tasco 7T scopes which all have the black crinkle finish along with the Space Scope black crinkle finish models and also Charlie's S5 black crinkle finish scope, I still believe my initial guess could be correct.
This is based on the following details that I've noticed on each brand of scope:
(1) The most obvious and maybe most important detail to me is that only the Astro Optical S5 and the Tasco 7T scopes have the two adjustment set screws above and below the model name tag on the focuser housing. All of the Space Scope models do not have the adjusting set screws.
(2) These Astro Optical S5 and the Tasco 7T scopes all have the gray plastic knobs on the focusers and the RA/DEC slow motion knobs. The Space Scope models have either all plastic knobs or they can also have all metal knobs as shown in MikeRam's photos.
(3) Based on the sample of scopes I've have documented for these particular models, the Tasco and Astro Optical do not have the engraved magnification on the eyepieces. The first Tasco models having the magnification engraved on them are the volcano top style of eyepieces. My Tasco 304 Power dated May 1959 is the earliest example of this model I've seen so far with the magnification engraved.
All the Space Scope models seem to have the magnification engraved on the tops of the eyepieces for the black crinkle mounted scopes.
(4) Looking at the 0.965 visual backs supplied with these models, only the Space Scopes seem to have a version that uses two thumb screws to secure the eyepiece. All the Tasco models that I've seen on these models have either one thumb screw or use a friction fit using a saw cut.
(5) With respect to the engraved lens cells, the Astro Optical, Tasco and Space Scope models can have the word "Danchyka" engraved on them, but also many do not. In some cases, the scopes with the lower serial numbers on the focusers appear to have higher serial numbers on the engraved lens cell, an inverse correlation if you will.
As always, if someone has one of these scope that contradicts my documentation, please let me know as I can only speak from the samples that I've documented.
Stephen
