Not possible, guys, sorry. If you do cut a hole in the top, you're going to ruin the stove. However, you can do something like this:http://nepacrossroads.com/about8124.html
It's woefully ugly, but works like a charm. I went from keeping my basement at ridiculously high temps in an attempt to heat the upstairs to pretty much evening-out the whole house and dropping the t-stat by six degrees or so. We can watch TV with our clothes on now. I'm sure if I replaced it with black pipe it would look a lot better. Considering that this cost about $15 and took 10 minutes, I'll keep it.
Come to think of it, I have no idea that path the air takes from the back of the stove to the front. Always wondered, though. Maybe cutting a hole in it is possible, but I have no idea where.
Mine's been running since 1986 (I hate to say this) with very few problems. Original everything, I think - it came with the house when I bought it ten years ago. I have the crack right down the middle of the grates, but it's never harmed the operation. Please tell you friend that the flat part under the stovepipe collar (where you were looking) HAS TO BE CLEANED a few times per season - I usually do it around Christmas, March, and the end of the season. If he doesn't, the flyash will accumulate in there like a snow fence and block the flow. CO all over the place. Also screws up the draft. The newer magnums with the sloped roof do not have this problem. Also, his stove probably does not have a restrictor plate over the combustion blower. You'll want one on there. I made one out of cardboard, then later on plugged the comb blower into a speed control and now run it 24/7.
It's a good stove, I think. If you need the manual, let me know. Anything I can help with please ask.