Updated: 10-Dec-2019
From Appendix 10: It is "Aktiebolaget Enoch Thulin Aero-fabrik" (see Thulin). A Thulin Type A engine is displayed in a Swedish museum, see the photo below.
"AETA-Thulin de 90 CV (Lic. Le-Rhone 9C)"
Engines of AETA
Model: Thulin A
"AETA-Thulin, 90 CV (Le-Rhone 9C licence)"