Studies in Kyo Goto by Kasahara Koju and Akimoto Shigeo that is why there are

that is why there are visible signs of wear

First one seems to be "天" (Heaven) and second one "王" (king)

To read more about Minamoto No Yoshitsune and his life I recommend "Samurai Raising" by Pamela S

by Fukushi Shigeo

Based on the  examination of this piece I would say It was made by one of the last generations

Studies in Kyo Goto by Kasahara Koju and Akimoto Shigeo that is why there are"Studies in Kyo Goto" by Kasahara Koju and Akimoto Shigeo. This book is dedicated to side branches of famous Goto family. Inside we will find everything we might look for in a book like that. There are good quality photos with close ups, English description of every item, 19 pages of history of the families and one chapter with comparison of real and fake signatures. Condition: very good