Dear Grant - What an astounding triptych woodblock print you have. As you know from the description this illustrates a scene from the 16th century Kabuki play 'Meiboku Sendai Hagi'. Yours scene takes place in the Palace. This block was executed by Utagawa Kunisada I (aka Toyokuni III) (Japanese, 1786–1864). This link will take you to a synopsis of the story: https://www.kabuki21.com/takenoma_goten_yukashita.php.
Triptychs from the story pop up for auction once or twice every year and are usually estimated in the $300 - $500USD range. Because your example is mounted to board, you can expect roughly half of the average.

So let me know if you have any follow-up questions and have a lovely evening.

Sincerely,

Erin-Marie