Where is Gujeolpan sold?
Is that just a divided serving dish, or is it used to cook in as well? I have a few suggestions for you, I live in Seattle, and we have a lot of small Asian markets, but also have a couple of large Korean grocery stores called HMart, that carry a lot of kitchenwares also. I have shopped there, but I also bought their KimChi Chronicles cookbook and DVD on line, which they didn't have in the store. However, when it comes to cookware, they have a lot more in the stores than they do on line. Check their locations map, if there isn't one in your area, I think I would try to email the picture to them and see if they would find it (I did just put in "Gujeolpan" in the search on Hmart.com, sorry, no luck).
We also have Uwajimaya stores, which are predominantly Japanese, but carry lots of products from other Asian countries. They are in Washington and Oregon (Hmart has locations in a lot of other states). And we have stores like Ranch 99, plus lots of small ones, that would be likely sources if you're in our area. I would bet that California also has a lot of options, as well as Illinois and New York, or anyplace with large cities.