Sorry to hear of this terrible situation.
It is possible that the impact was absorbed mainly by the camera mount, as the metal mount ring has been deformed. The lens may have been damaged also, so it should be tested (perhaps on another camera, or later when your K-3 has been repaired).
You might try to straighten the metal mount, which may be removed easily from the camera. Making it flat it may be difficult, however, owing to the shape of the mount (it is not a simple flat disk). The strained metal might not easily return to its original shape.
As for the possible damage to the screw holes in the body, see a recent post by DaveR for a superbly detailed description:
https://www.pentaxforums.com/forums/114-maintenance-repair-articles/306083-k-...nt-repair.html
Considering that other mechanical damage may have been caused within the camera, the camera should be fully tested for optical alignment and mechanical functions.
Like you and jatrax, I am fairly handy at fixing things, and have made several repairs to old SLRs and lenses. In this case, a repair by a service centre would be my recommendation.
How did the Lowepro case break - a buckle or a snap? Such a failure is troubling.
Good luck. Sorry about the damage.
- Craig