Could it be that TY 80, #Y8035, was the only two drum 'high lead' yarder that Ross produced at Eugene.
Scans from the factory book for TY-80-2D #Y-8035. See there Torkel, even the factory called it a two drum machine
View attachment scan0003.pdf
View attachment TY80_2.pdf
View attachment TY80_2_1.pdf