History of my Bentley piano

[pomwi]

I inherited a Bentley piano with the following markings and would appreciate details of its history such as age.

Bentley
Patent 21430
Resonoura Sound
571097
66934

I believe the piano was purchased in New Zealand in the early 50's. Thanks for any information
Phil Norman

[Bill Kibby]

The larger number suggests that your piano was made in 1940, but without photos, I cannot guess if this is likely. The smaller number does not conform to the published numbers, which are wrong anyway, as mentioned at
http://pianogen.org/numbers.html
because the Bentley name was not used until 1930. Patent numbers do not help us.