your cnh dealer will have one of course.
the rad on my 68 3000D is a repalcement.. it came from an online supplier.. but the seller couldn't remember who he ordered it from..
the one here looks to be ok.
the N series radiators have more of a problem with fittment .. i don't here major concerns about the 3 cyl rads as much as the N series.
hopefully it can be fixed.,
is it in the core? tank ?
if the rad is solid and not rotten.. many times a sinple single tube or 2 damage inthe core can either be fixed and flow.. or if nothing else.. pinched off. and sealed. former is better of course.
I have an old ford 850 that no longer is a mower.. but is now a loader/backhoe only.. so doens't run at full rpm all day.. it's radiator ate a fan once.. i have half the tubes pinched off.. :) probably mor elead and tin on that rad than brass and copper .. but she still holds up. if it ever gets damaged again I'll have to put a new one in though.. :)
best of luck