Thanks for the info. On this particular truck the paint is original as it was RCAF. A lot of these trucks, including the one we're restoring ended up in the Yukon after the war. So I'm wondering if the mod was done to allow them on civvy street at that time. A friend of mine has kindly removed the whole unit and is bringing it back to to the valley next week so I'll be able to check for a manufacturers date. On this one, the arm was connected to a cable of some sorts and there is a bracket, missing the arm inside the roof
There also is a fair lead bracket in the back of the cab roof and I can't seem to be able to load that picture right now but I'll keep trying.
Rob