The rocking chair in this photo [Likely Solved]

I remember it played a nursery rhyme like a music box when both armrests were gripped.

That’s my sister and I visiting my great-grandmother in her infirmary in *1975. The chair wasn’t meant for visitors, but for children housed in the infirmary.

The chair had metal armrests that acted like actuators, and a metal box under the seat that played nursery rhyme songs like a music box when both armrests were gripped and the chair rocked.

Was this a common thing, perhaps mass-produced, or just something jerry-rigged by some guy?

Have you seen anything like this? Thanks!

(Sorry for reposting; my post went wrong last time.)