@Neville Chaim Berlin –
Firstly: Actually you wrote, “The Mishnah Berura is meikel (in how he poskens) on just about every single halachah you mentioned.” Sorry, I had no idea that you were only referring to tevilas Ezra.
Secondly you write, “We posken by sifrei halachah, not by “gedolim biographies” and pictures.” The OP was about hanhagah not halachah. Therefore the rule of “shimusho gedolah mei’limudah certainly applies here as do any and all historical records.
Thirdly, the Mishnah Berurah indeed wore a long coat (actually discusses the קאפאטע in hilchos tzitzis describing it as a beged which has gained much popularity, had longer, noticeable peyos, wore a gartle (at least on Friday nights (the family still has the gartle), and never missed tevilas Ezra.
All this points to the fact that peyos are not new, and are not only Chasidish. That was the jist of the original thread.