Doubt it. They look nothing alike and share no common features. Even their abilities are innately different. Shisui was famed for his powerful genjutsu while Tobi's abilities are centered around Space-Time manipulation. As for Kagami being either one's father, who knows? For all we know, Obito's father could be the shop owners. It really isn't relevant either way.
So how do explain the 1st & 2nd Hokage brothers? They look nothing alike and share no common features. <_<