Welcome to the Lawn Boy forum. This is the place if you need help. There are some really good guys on here that like to help out. My very first Lawn Boy was a 1976 model and the carb looked like yours. My air cleaner cover was part # 608791 or 608814 and the foam filter was part # 607580. They are available on Ebay. I could be wrong about this so don't order anything until someone more knowledgeable chimes in with more info.
Thanks for the reply...checked on eBay and the 608791 cover looks to be what I need.
Seems that the actual air filter elements are available after market which is good.
Are there still ignition components made for these or just NOS?
I don't see any drawings for your model on the lawn boy site where I always look up parts. I don't think all D series engines take the same coil. From what I have seen, they are pretty expensive. Some of the small engine part stores say they are discontinued but you can still find some on Ebay.
Good luck.
Jerry