Yes it would be interesting to see a simular scene next winter with the Scammell with the rear tracks fitted , that just might have solved the traction problem , plenty of power it was just loosing traction due to the tires being unable to push the snow out of the way along with the drag of the depth of the snow on the axles.
Hows the snow in the area where you were pushing your way though the drifts now ? Nearly all the snow in my area has melted , had upwards of 4' drifts and an average of 1' now traces or less remains the drifts down to 1' or so . Been 40's to 50's f the last week .