I can make two models for you that have the two different radii that you need. However, there's a problem. To have this printed in stainless steel it will need quite a bit of editing. Take a look at the design rules for stainless steel
here. The minimum thickness for the whole base needs to be 3 mm, you're currently at about 0.533 mm. Also, take a look at your engravings, they need to be 1 mm deep by a minimum of 1 mm wide, yet there are engravings in your design that are as small as 0.3 mm. Although,0.3 mm engravings will work for sterling silver, it won't work for stainless steel. What will happen is the engravings will be mostly filled up with material.
You can try to see if Shapeways will print it in stainless with those engravings that you have, but if they do, you might be disappointed by the results. Before seeing if they will even do it though it'll need to have the thickness increased to 3 mm.