5-inch Photo-Equatorial Refractor on Field Tripod: Complete with equatorial mounting and slow motion controls for both declination and right ascension, flexible cable for auxiliary R.A. control, provision for coupling clock drive or synchronous motor drive, setting circles with veniers, wooden tripod, Super rack and pinion focusing mechanism, 10x40mm viewfinder, 60/700mm photographic guide telescope, 10 coated eyepieces, Model 220 Astro Camera, sun projecting screen set, sun glass filters, Hershel Wedge, erecting prism system, Super Unihex, Unibalance assembly, dewcap and dustcap with solar aperture diaphragm.
The photos below were taken when this Model 510 was owned by Jim Craft, Texas, who had it in his possession for 34 years. Originally, Unitron Company donated it to a Baptist School, and then it was passed on to a number of individuals (one in Dallas, Texas and another in Euless, Texas) before Jim acquired it. Tom Terleski, Ohio, acquired the scope in 2013, completed a restoration and then passed it along to Dave Komar, Culpeper, Virginia in 2015. John Graham, Dayton, Ohio, is the current owner.
This Model 510 has the electric drive option. Current accessories include the Super Unihex, Unibalance Assembly, Model 220 Astro Camera, Duetron, 10X40 Viewfinder, 60/700mm Guidescope (with 25mm EP), Sun Projecting Screen Set, and nine of the original ten EPs (5mm, 6mm, 7mm, 9mm, 12.5mm, 18mm, 25mm, 40mm, and 60mm…still missing the 4mm).
Owner – Jim Craft – OTA
Owner – Jim Craft
Owner – Jim Craft
Tom completed a comprehensive restoration of this beautiful scope in 2014. This restoration project is documented on the Restoration page. Photos of the results are below.
Owner – Tom Terleski
Owner – Tom Terleski
Dave Komar, Virginia, procured the scope in April 2015 during NEAF 2015. He has plans to “fine tune” Tom’s restoration effort, gather up some of the missing original accessories such as the full size tripod and a complete set of EP’s, and finally to “ops check” the electric drive and possibly even the astro camera. The ultimate goal is to locate the scope permanently in an observatory setting.
Owner – Dave Komar
This model 510 came equipped with the electric drive motor shown here. It currently operates but is noisy and over extended periods (more than an hour) gets relatively warm. I plan to take it apart and clean and lubricate it first before considering reconditioning it.
The case that houses the OTA and the 60mm/700mm guidescope is both beautiful and large!
Accessories include: the Super Unihex with 60mm and 40mm eyepieces, plus a collection of .965 eyepieces (5mm, 9mm, 12.5mm, 18mm, and 25 mm); a Duetron, the Astro 220 camera, and various extension tubes. 
The telescope has been most recently mounted on a Losmandy G-11 mount using a procured set of tube rings and 24 inch Losmandy dovetail. 
For size comparison, the line up of 2.4 inch, 3 inch, 4 inch, and 5 inch Unitrons: 