I'm looking for a router bit (preferrably from named brands like CMT, WPW, Dimar etc) to get a profile of an arc of a large radius, something like 55-60mm and of a chord length equal to something about 30-40mm. This profile (or the one that looks very close to this) is often used on a picture frames you can find in the local stores.
Here is the sketch of the profile I'm trying to get after milling one plane of the rectangular piece of wood with a router:
I have found many bits with a profile that is very close to this one - CMT 954.509.11 (details here - http://www.cmtutensili.it/show_items.asp?pars=RB~7/8/954~2~2~1), but the largest radius I can get from a bit like this is about 19mm.
So, my question is - does anyone know the particular bit that fits my needs described above? Or, alternatively, is there another way to get this profile?