I've swapped bars and chains between an 011 and an 021 -- the bar mounts are the same, but you'll have to check to be sure the chains are the same. The ones I swapped were both 3/8 lo-pro, and I'm pretty sure that was the standard setup for both.
Some of the old bars for the 011 series didn’t have the oil hole above chain adj pin hole as they fed oil via that oil while 021 and newer needed hole above