S90: Main Jet Mystery

What's tough with this S90 is that if I see something that doesn't look quite right, it's hard to know if it's just supposed to be that way or if it's one of the many shadetree mods that the previous owner made.

All the carb diagrams I've seen seem to indicate that the Main Jet and the Needle Jet Holder should be two pieces.  But the one in the Keihin carb looks to be a single piece.  I've actually found it online and I think it's a more modern Honda type of jet.  Not positive, though.