Got one just like that. I have enjoyed it for years. Good find. The only thing I disliked was the small box for wood chips. I replaced mine with one I picked up at Lowes. It was about twice the size for more smoke flavor. Don't beleive the temp guage.
I have owned a GOSM for years and it has served me very well indeed. I don't know about your cast iron skillet you would have to get the temp up there pretty high to make smoke. I got a small about 9" around pan I used for chips and it works really. You will like it alot it almost a set it and forge it type of smoker. I now have a smke vault 24" and the gosm has been made intoa suasage / bacon smoker with a single hot plate added.
Nice snag I also have the same one. I second the little chip pan I hate mine. I use a cast iron pan with a lid now. For some reason my buddy bought one of these smokers and it was just a bit bigger than mine and his came with a huge cast iron chip pan. I guess he got lucky.
FWIW my cast iron skillet in my smaller drawered gosm works great, I can make good smoke on low all day long, I just preheat the cast iron when I preheat the smoker, it doesn't take 10 minutes to have a good stream of tbs.