It could maybe use some gear oil before use since I believe it has been in storage for quite a long time (likely several years) but nothing appears corroding or rusting at all. I disassembled the tines for the pictures to try to get some detailed photos. The tines have the number 4601 713 4003 A on them and the shield has the number 4601 713 4500 B. The gear body has the number 54L26 on it.
You can see all of these in the pictures. For straight shaft STIHL trimmers. IT IS YOUR RESPONSIBILITY TO MAKE SURE THIS MODEL WILL FIT YOUR STIHL TRIMMER BEFORE PURCHASING! The item "STIHL Tiller Cultivator Attachment BF Model Weedeater Trimmer Straight Shaft Gas" is in sale since Sunday, September 1, 2019. This item is in the category "Home & Garden\Yard, Garden & Outdoor Living\Outdoor Power Equipment\Tillers".The seller is "ninja4086" and is located in Illinois. This item can be shipped to United States.