So do I understand this correctly: the three stickers are not all equal, even if they all mention an annual inspection. Instead, one sticker stands above the others, and that is the one that says "I certify ... inspected ... airworthy condition."
If that's so, would it still be possible for various shops to participate in the process of inspection, as long as the last of the shops involved writes the certification quoted above?
Here's an example scenario:
As the due date for the annual inspection draws near, an owner suspects his plane needs an overhaul of the engine (or prop). Rather than starting by taking the plane to his local shop, who would inspect the engine (or prop) and pull it off for shipping to a specialty shop, the owner instead starts out by going directly to the engine shop (or prop shop). The owner asks this engine shop do an annual inspection of the engine, and if discrepancies are found they are remedied right there, perhaps by doing an overhaul. The owner might choose a shop like Western Skyways or Zephyr that specializes in engines but also has a general airframe shop that can do the removal and installation as well as inspections. However, the owner doesn't want his airframe inspected at this shop that's mostly known for engine overhauls; he prefers his local shop because it specializes in his particular airframe. So, after the engine shop is done with its work and offers some kind of certification that the engine has been inspected and is airworthy, the owner flies or tows the plane to his favorite airframe shop where the remainder of the annual inspection will be done. That final shop renders the final certification that the plane has been inspected and is airworthy.
Here's the question: in rendering that certification, could the final shop rely on the engine shop's inspection (which was made after installation of the newly overhauled engine at the location of the engine shop), or must the final shop carry out its own inspection of the new engine by cutting up its oil filter and testing its compression, etc.?