Domestic F was offered until 1992 (not 1980). 3-class domesticwas only one or two years (introduced 1990 or 1991).
Seats were 8 seats in 737/727/320 and 18 seats in AB6/310. Similiar to the seats u.s. carriers offer in domestic F.
Food was mostly hot food (even on short flights like FRA-MUC) with linens.