The reason that they command much less of a premium because there simply is a lower demand for them. They are more expensive to run, reproduction parts are less plentiful than other vehicles, they require larger equipment and a higher degree of mechanical know-how to maintain, and they take up a lot more room than the smaller ones. These unfortunate vehicles which served quite proudly and effectively are often relegated to back corners of fields to rust away. There is one up towards Norland that I see quite often working on the property with either an oil or water container in the bed. Unfortunately even armoured vehicles don't command the sort of prices that you would expect for quite the same reasons. When you restore a vehicle you are never getting your money out of it if you decide to sell. They are laybors of love that you keep, enjoy, maintain, and share with others.
You definitely need to do this resto! There are quite a few of us in southern Ontario who would definitely lend a hand.
It looks like you have a great base vehicle with even original lights still installed. Do they run the 24V systems? How much were you left with in terms of original bits and components?