Nobody can tell you how many were made, not even TC. As PA said, all ML records were lost in the '97 plant fire. The main manufacturing building was heavily razed and other buildings destroyed, including the ML stock making shop, barrel machine and blueing shop, the repair shop, router shop, machine oil and powder storge, test fire shop, etc.
Can tell you not very many Cougars were made because it was dropped so soon after being introduced, a strong indication that they were not selling because of asking price. So they were a very short lived model, only cataloged in 1986 and 1987 if I remember. Might have still been some on shelves for a few years after with deaerls or even TC as they did not loose thier completed firearms wharehouse in the fire. But what's out there is all there is. There are other TC models that are far rarer, but this is a great score. Serious collectors would pay a premium for a Cougar in mint condition, way more if still NIB. So you most certainly did get this one for a good price. BTW, it's high grade stock would have been from wood processed in TC's own sawmill and dried in their kilns before going to their stock shop.