I would speculate that they did, because

• all Ruger Security-six, Service-six, and Speed-six models built during the Bicentennial were marked with that logo, so they weren't rare at the time
• Rugers were fairly popular with law enforcement in that era--semi-autos had not yet taken over (sorry kids--there was no such thing as a Glock back then )
• and of course, .38s and .357s were the mainstay caliber of law enforcement then

And since all models in 1976 were marked like this, I suspect they were not considered collectors items at the time, though they probably are today.