Need conversion kit for creda ggh 102 stovetop to propane?

I needed this conversion and an appliance repair man had some spare parts that he used. It's just the orofice (opening) that needs to be changed (I think the propane one is a smaller diameter hole). He charged me cost of labor and kept my natural gas parts in exchange for the ones he had. The problem I'm having is can't get the low flame setting correct. Stove puts out too high of a flame and tends to burn the food easily. Repair man has tried 3 times to adjust it and it won't turn all the way down he says.

Alice
August 2017