still in use commercially....

[maple_leaf_eh]

http://www.heavyequipmentforums.com/...-in-Nanaimo-BC

A whole lot of knowledge on the heavy equipment forums dot com. I keep learning more about Madill every time I scroll through the 107 pages! There are a few NZ spar yarder posters on there too.

[maple_leaf_eh]

http://en.wikipedia.org/wiki/M4_Tractor

One recurring theme is which chassis' were used for these forestry vehicles. Here is part of the answer, with some maker's names and model numbers. GM Philpott became Finning. Now we know another piece of the puzzle.