I have a 520 SP 1983 barn find. Put new gas/ oil spark, air filter in it and it ran. Took it to my tuner to be gone through and he fired it up gave it back to me and said run it did not turn a screw. He is 88 and winding down after a fall. I found a OEM chain stop for a 1990 262 XP on OPE. The plastic one. My 028 AV Super never needs parts knock on wood. CS 3000 can get cantankerous/ usually carb related. MS 201 C 10+years old maybe older never needs anything but a scary sharp chain. i would like to get the chain brake working on the 520. Today I am 63. I was born during the Cuban Missile Crisis. Mom thought the world was going to come to an end. I guess all that stress coming through my umbilical cord is why I am the way I am. My Parents sang HB to me, they are 88 and 87 I am blessed.