An interesting article, but it is flawed. The Swedish Chef was not based on an actual Swedish chef.
Jerry Juhl's own words:
"I wrote, rehearsed, rewrote, brainstormed, and giggled uncontrollably a thousand times with Jim Henson as we dealt with the Swedish Chef, and I never ONCE heard him mention an actual Swedish chef, especially one that claims to be Charleton Heston's golf buddy! I mean, that's a story Jim would have told! I can't remember where the genesis of Swedish Chef was. I think it was an idea with Jon Stone around the "Sex and Violence" show, which I didn't work on. But I do remember that Jim spent a couple of weeks listening to Berlitz tapes while commuting to get his babble perfected. Then, much later, I actually WROTE the babble! Heck, I come from good Danish stock, which Jim and I decided made me an expert in Scandenavian linguistics."
http://www.muppetcentral.com/news/2001/070301.shtml
And from Brian Henson:
"Jim Henson had this tape that he used to play which was "How to Speak Mock Swedish". And he used to drive to work and I used to ride with him a lot. And he would drive to work trying to make a chicken sandwich in Mock Swedish or make a turkey casserole in Mock Swedish. It was the most ridiculous thing you had ever seen. And people at traffic lights used to stop and sort of look at him a little crazy. But that was the roots of the character that would eventually become the Swedish Chef."