CB160 and 175 are 428 IIRC. 530 would be huge and heavy by comparison. Are you sure about that? Even the CB77 only used a 525. Maybe because it's a CL off road ( : ) they used a thicker chain. Check the parts list.
To close out this thread I was able to get a look at an original chain and lo and behold it was stamped DID 520D S. I assume the DID is the company and the 520 is the chain pitch and the S is the style of chain.