Don't know about that expression...but Riggs would almost have to be smiling. That's why most Riggs customs don't look like Riggs.
It's like trying to build Jack Torrance with a blank-faced or open-mouthed Nicholson.
They're both nuts. I'd buy a smiling Riggs. Then I would want a Glover to say, "h-h-hey RIGGS!"