The chair consists of 8 pieces, made with 6 different molds, the making of this ancient garden chair was not easy.

Bibliography:

CAST-IRON FURNITURE - Georg Himmelheber - Philip Wilson - 1996
Photos 113 and 114 - Edinburgh, Charles D. Young & Co., c. 1850

GARDEN ORNAMENTS and Antiques - Myra Yellin Outwater - Shiffer Publishing Ltd - 2000
Page 186, two photos with text: Late 19th century, cast-iron seat.
American. It is very unusual to find a bench this small. Hobensack and Keller. PAUSE
Myra Yellin mentions America as origin but does not refer to the production which was certainly Scottish, this model was exported to America by C.D. Young & Co in the second half of the 1800s.

Messrs Charles D. Young & Company. Illustrated and descriptive catalog of machinery, implements, tools ... iron architecture, bridges ... c. 1857-8
We found the original catalog of Charles D. Young & Co, we publish at the end of the photos, the title page of the ancient catalog and page 74 with the drawings of the bench and an armchair.
The category is HORTICULTURE and JARDINERIA.
If you are interested we can provide you the scanned catalog in PDF of 37.4 MB.