Dear Gary, you bought a fine Muromachi kabuto, papered by the NKBKHK as koshu tokubetsu, This is not nothing. Takemura sensei was a member of the Shinsa team, and he is familiar with Yoshimichi’s work. I trust his opinion.
Yoshimichi is one of the sasaku, one of the 3 best kabuto smiths ever.
About different generations, nothing is known. There is however a difference in his work, what does me think of a production by the master himself, and a production of his workshop., but this is only an assumption. Since it is a grandmaster, you should expect a masterpiece. I saw only +-5 of there incredible masterpieces during my career.
I can not judge yours on these pictures, but at first glance it is not impossible that it is made by the master himself, or first generation (according some theories.)