Just for fun, here is my D7 (left) next to my D50 (right). The D7 is LOUD. The motor probably needs servicing? The bag on the D7 is a factory replacement. The emptor on the D7 is probably from a different Kirby but I am not sure which one. It is dark brown on the bottom instead of tan.
I have a sani 7 just like yours i believe that to be the original emptor as mine looks the same as yours. Mine is quiet loud as well i made a video on it and was also told the bearings are probably shot. O would replace or service of i only knew how but other than that never had a problem with it and still runs like a champ.
Hey
Your emptor has sweet aire and it has 3 prong. Its 516 to 562. It fits 562 cord so maybe emtor not bottom just metal might be original to vacuum since you have rare cord to boot.
Nice job on vacuums very nice.
Les