Hey neighbour! (I'm in Regina). Sorry to hear about your truck.
I'm also sorry to have to tell you that SGI will write off anything over 5 yrs old. They will value that at about $1000, give or take.
As for buying it back and fixing it, SGI has some screwy rules. Once they write a vehicle off, no matter what the damage, the whole vehicle has to pass a safety inspection in order to plate it again, and they get stupid about what doesnt pass!
You can pretty much count on replacing steering, shocks, brakes, any leaks, windshield, u-joints, They wont even pass it with rust on the body!
I have a diesel pickup shop and see accident victoms and out-of-province trucks (also require safety's) all the time, usually it costs more to fix than buying new.
Have a look at SGI salvage site, click on the vehicle name and it will bring up pics. You can see some fairly new, "minor damage" vehicles that have been written off. Especially the "1987 GMC" near the end of the list. Bent rear bumper=write-off!
http://www.sgi.sk.ca/lcgi/salvage_bid_site/list_bid_items.cgi?searchFor=bidItems&stores=All