Looking for Astros 1978-1980 watercolor art pieces

Back around '78-'80, the Dome souvenir shop would sell these wonderful watercolor prints of Astros players and manager Bill Virdon. They weren't quite 8"x10", maybe 5"x7". I vividly remember the JR Richard one because it was based off of the photo of him holding 8 baseballs in one hand.

I haven't seen these pieces in over two decades. I've tried to find them online. Does anyone know the artist's name and/or how to get a hold of these?