I finally received the 1077865M91 mounting brackets for the 1240 and they were a direct bolt on under the rear axle.
However the so called Frame Asy (or what we called in this thread rails) are about 5 inches longer. I can cut them and weld them, but I decided to check if anyone would need those together with the mounting brackets.... They are for the 1160/1180/1190 tractors according to the agco parts books .