My rule of thumb is to replace anything rubber if you've got the parts apart, unless you know for sure that the rubber parts are new or relatively so. But those radius arm busings are expensive! And not easy to replace.
As a side note, when disassembling my 1966 BJ8, I discovered that it had no radius arms, and no panhard rod, and no radius arm attachment points on the chassis. The rear end does have the radius arm brackets. So I'm having to weld in all chassis attachments for the radius arms. One knowledgable person suggested that when this car was assembled, the factory just had an earlier chassis on hand, and built it without the radius arms or panhard rod. Yes, I have verified the chassis number does conform to the car number and the year of assembly. Anyone ever heard of such?