I have some Stihl tools to trade. they have the parts numbers on them but some how my dumb ass stihl orders them. let me know what you have. really interested in other tools or service manual
one that you can see part number is 1106 850 4201
I think he/she meant for the part you can't see the number for.
1106 850 4201 is the the leak test flange (088, MS880, 090) near the center of the image.