I e-mailed Herrett's last night and got this response today:

"Our current custom stock maker is not sure if the stock was made by us. She has been here since 1975, and if it was made by us it was made prior to that time. From the pictures, she said it looks to be made for a Colt Python."

Based on the "Gagne's" jig holes on the inside of them, I'm gonna go with Roper's...