Contact information for Yamato Museum

Hi Tom.
You can call the Yamato Museum on this phone:
0823-25-3017
More phone numbers here: http://yamato-museum.com/%E3%81%8A%E5%95%8F%E3%81%84%E5%90%88%E3%82%8F%E3%81%9B/%E3%81%8A%E5%95%8F%E3%81%84%E5%90%88%E3%82%8F%E3%81%9B%E5%85%88%E4%B8%80%E8%A6%A7/

They don't have an official email to contact in English but maybe you could try filling this contact form:
https://yamato-museum.com/form/ym-otoiawase-form.html

If you can't write in Japanese, write in English and hopefully they will be able to get someone to help to reply.