...

From the big horizontal SPRINT monocylinder ?
maybe yes ... but also maybe not .
Well : i have searched in my books ( at the aermacchi chapter , this time

)
and look what i found :

this is the 1971 panel production .( "the big book of harley davidson" , by T.C.Bolfert )
the aermacchi and the Sportster seats really looks the SAME .
but give a close look to the red arrow i have added on the pic : it shows the seat BRACKETS ( one on each side ) bolted to the sporter's sabers ...
i have the exactly SAME brackets on each of the 3 seats .
DOES SOMEBODY HAS A BETTER PIC THAN MINE ?????
( anyway : i know by now tey are NOT K seats ....

)