For Sale is a New Old Stock Genuine McCulloch Chainsaw Clutch Thrust Spring Washer. 

Fits:
1-41
Mac 15
1-42
1-43
1-45
1-46
1-51
1-52
1-50
1-53
200
250
Super 250
Super 450
Super 550

It may fit others so please ask if you are not sure.