That's some pretty bad news. That is exactly the same as my 78 CJ5 factory skid, and the holes are the same as well. As has already been said, that skid is meant to hold up your driveline. If I were you, I'd check your motor mounts because your engine was holding up the rest of your driveline with a whole lot of torque on your motor mounts.
Also, since the skidplate has to be removed in order to take out your tranny, t-case, or get at the clutch/bellhousing, welding it on is a pretty poor solution of the PO. Good luck in sorting this out.
1978 CJ5 - 304 V8 - Twin Sticked and sitting on 35's
2010 JK- Rock Krawler 2.5" on 35" KM2's