I've changed out several engines one of which was my 07 DL1000 from an engine I bought off Ebay. If you are capable of an engine rebuild it shouldn't be a big deal to swap out this engine for you, It really is a piece of cake.. Take off the plastics and tank, drain and unhook the coolant system, unhook the throttle body intake and electrics, your drive is already off, unbolt it from the frame and drop it out. As mentioned earlier take a photo diary of the tear down and you'll be good to go..
Not that I would discourage you from a legal battle but the time and money you put into it may be more valuable putting in a good used engine and getting back on the road, particularly if there is any kind of chance you might lose.
As convenient as dealers are I just plain don't trust the 21 year old that's working on your bike. When I buy a new bike, atv, or snowmobile the first thing I do is take it home and go through it to make sure it was put together correctly. My last two Vstroms (from different dealers) both had issues. I was not thrilled with the handling of my 2014 new and when I got home did my check over. 15lbs air pressure in both tires. My 2013 DL650 they forgot to tighten the brake master cylinder saddle and while driving it home the mirror and brake slid forward and down, along with the clutch adjustment nut wasn't tightened and spun all the way day by the time I got home. The last snowmobile I snowchecked I went flying over the hood when loading it my trailer because they forgot to tighten the handlebars. It seems like there is always something not right and because of that I just don't trust many dealers. I have one Suzuki dealer I now frequent and I now trust them, but they have had to earn that trust.
On my 2012 Vee Adventure when I got it home the front axle pinch bolts were loose. Not to mention the side cases were on backwards.
2012 DL1000 Adventure (Tinkerbell)
PC-V, TRE, CR8EIX , ECM, K&N, RDL, PR4, PC-8, EB H4, WERKS, Madstad 22", 17/43 gearing, AdventureTech: Fork brace, shelf, mirror extenders, SpeedoDRD, wheel spacer, Head's-Up voltage monitor, Goldwing pegs, Sonic 1.1, Wolo Bad Boy, ExTuff Helmet Hook.