Picked up another of those Chicago Specialties 5/16" hex screw starters, and a sticking Mountain double flex head ratcheting wrench.
Is a 13x15 mm size, the larger end was definitely having issues. Paid $9 and change, took a chance. When working on it I noticed a sliver of metal coming out of the end while spinning it. It was the internal snap ring! managed to get it out, but it was unuseable. So I took a stab at fashioning another snap-ring out of a piece of suitable sized SS wire. Worst came to worse the 13mm end will still operate. Got it together, and it works like a dream! Not what I would put a whole lot of torque on, but as long as it is - with a recessed side and flex heads - could prove very handy. Simple frankenstein ratchet design.