did you google it ?
my mother had a similar one among her many, many sewing things that
was passed to my brother’s wife after she passed.
maybe google can turn up a pattern:
https://www.google.com/search?q=vintage+pin+cushion+chair&rlz=1C1BLWB_enUS651US651&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwi_mfDyg7XZAhUJ3FMKHUSgCPMQ7AkIbA&biw=1191&bih=603
this is similar to what my mother had. my father made the wood frame chair
and she handmade the quilt like cushion. both of my parents were great craftsmen.

Drek – get some cardboard and play around with designs that you like.
cut out the pieces full size and glue them together. if you like the design
and style, use the cardboard as a template to cut from 1/8” plywood.
the overall size is about 4” square and 5 or 6” tall.

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-- there is no educational alternative to having a front row seat in the School of Hard Knocks. --