Modding Robbie the Robot kit to look like he did on Twilight Zone

I just picked up this Polar Lights Robbie the Robot modeal at the flea market. It only includes the face they used on "Forbidden Planet," but I'm thinking of trying to mod him to look more like he did on the Twilight Zone episode "Uncle Simon." I've never done this before. Any suggestions before I try to start sculpting the face?
Forbidden Planet Robby the Robot Model Kit - Round 2 - Forbidden Planet - Model Kits at Entertainment Earth

Here are some pictures of the way he looked on TZ:




I also noticed that there is a toy version of Robbie in "One for the Angels." I saw a windup one on eBay. I wonder if that would be about the right size - It looks like they just added an eye to a miniature Robbie's head.

Very cool find. Wish stuff like that was at the fleamarkets here. I've never really modded anything like this. The one from twilight zone may be easy to do. Simply remove the forbidden planet head and make the TZ one out of styrene.

There is actually a model shop, inside the flea market. It's one of the few places I've seen kits other than cars, planes, and boats. You can get a table outside on Saturday or Sunday, or run a stand inside the building on Saturdays. The closest thing I've ever seen to it is the dirt mall in "Mallrats."
I've been eyeing the Robbie model for some time. Now that I found a place in the area to get the paints I want, I went ahead and got him. I know I can always get stuff like that online, but there's something way more pleasing about picking up the actual box, handing the man cash money, and walking out with something fun.

Cool project, post some pics of the kit.