I agree.

First off you most likely have a 1 inch threaded fork and headset with a quil stem at present. If you think you have anything different then you will need to measure the diameter of the fork's steer tube for yourself. We can't read minds or see things from here. A great resource for checking things out first before asking is www.parktool.com/repair . The diagram of the bike is loaded with links that will take you to other pages that have pictures of the different options and information on how to measure the stuff to find out what you have.

Without getting a newer threadless 1 inch fork and headset the only way you can switch to a threadless stem is to get a quill to threadless adapter. Once you have one of those and assuming you get a 22.6 to 1 1/8 adapter THEN you can shop for a 1 1/8 to 26mm threadless stem to fit a set of drop road bars.

On the sizes you measured and reported above they don't do us any good. The stem and clamp sizes work in diameters, not circumferences. Use a set of cheap calipers to measure them again. Once you measure this stuff then you'll realize what sort of stem clamp sizes you need.