When I went to the CE Spine Chart, it came up Heritage 250 for 46-51 and 52-57# draw weights. When I entered the figures to get to that chart, using the only option for a stickbow, recurve, it came up add 7# to your draw weight to enter the chart. That would make your adjusted draw weight 57#. It would put you right where you need to be with the CE 250.
Insofar as a footing goes, a 2512 would have a .366" inside diameter. A 2412 would have a .351 inside diameter. A 2312 would have a .335 inside diameter. A 2213 would have an inside diameter of .318. A 2215 would have an ID of .314. A 2217 would have an ID of .310. We're getting close to the .305, so I'll leave it to you to keep searching. Actually, the 2217 would probably be more than addequate. I couldn't quit, so a 2219 should work great with an ID of .30575.
Bill