Okay, I will preface this with I am a newb when come to building up bikes.
As I posted earlier, I picked up a 1986 Miyata One Ten in the trash. Need a rear derailleur and chain. Based on searches I think it was a Shimano Light Action RD (RD-L523). The bike has a Z-204 FD and L422 down tube shifters. Not familar with these shifters, are they friction or indexed. They click but not just a few times, like 17 times. Is this still considered SIS? I'm thinking not. Will a RD-L525 work with these shifters? I found a couple of these on ebay, but my research tells me these are 1987 SIS. How about the chain, where do I find a chain that will work? Thanks. Bill