Larry,
I would be a little concerned in using the same folks to recore the radiator again.
My radiator is also leaking at the rear, top of the core, but a little stop leak has kept us going thanks to Dave Atherton. Cannot see the actual leak point but don't think there are any hoses on the top of the radiator.
I have contacted two sources, Radiator Specialities (855.615.3002) and Source Engineering (541.343.0293) in Oregon. They quoted $3950 and $3911 respectively, plus shipping for an all new radiator. About a week lead-time to build. Part number on my radiator is RS 4847 from the coach information data sheet.
Personally, I am more concerned about the install and where I can find a reputable shop in the Phoenix area. I would rather not use one of the big dealerships if possible. Wondering if anyone has a suggestion??
Good luck Larry!