Venom offered a walnut thumbhole Innova custom in the late 80s or early 90s. I'm pretty sure the stocks were from CS of Sheffield (CS700 pattern). You could probably have ordered the stock separately from CS, if you didn't want the other Venom features (some kind of internal tune and a Venom silencer on a new or modified front end block).
Venom also made a bullpup Innova around the same time.