And now, looking for Mrs Nguyen Hien Hong, I found a Vietnamese page describing her collection, The name od the car is "Fiat Auto-Union". I also found this rather strange Foogle-translated description
"The unique car that she owned included Lambretta BerLin also known as Old Blue, Fiat produced only in 1956 AutoUnion in Vietnam or the BMW collection 3 wheel life 1954 with white-black version 2, Honda, Honda 65 rare lifetime lifetime 1965 or a unique level of motorcycle with copper overalls truss, the renowned C50 and. .."
Congrats to ropat53 !