Nice work May! It looks strikingly similar to a couple I've had.
This one I got in Seattle a couple years ago, the band hinge was completely rusted off, I replaced it with the hinge from my Ceramic Big Green Egg, notice the length of the bolts.
The people I got it from bought it from Pachinko Palace in Seattle and it came with the cookbook/manual the same copy as the Naked Whiz has for downloading.
It also resembles this one that I recently refurbished and just sold.
I have seen ash grates and damper tops like the one with yours as well as the ceramic ones.
The trolley cart looks the same, looks like they removed the casters and bolted it to a beefier frame.
The slide tops marked with Taiwan on them is a clue that they are Chinese made Kamados and not Japanese made Imperial Kamados, here is a link from IK describing "Imitation Products" in the third paragraph, so it possibly is an early Big Green Egg.
This page describes the difference in sizes of the Traditional Kamados due to the fact they were made by 3 different factories using different molds.
I'm not sure if there is a Uwajimayas in Vancouver, but they used to sell a lot of Kamados here too, you might want to snoop around the Chinese markets and see if there are any old ones.
Hook up with Brian Misko, he cooks on Primos in Vancouver, he might have a line on supplies.
Here are a few other BC BBQ teams that are in your area that may be some help.
Keep us posted on the work in progress!