The bolt holes on timing chain covers and oil pans are made from very thin steel and will distort if a PO tightened the bolts too tight.
Here is how I flatten any distorted bolt holes in an oil pan, timing chain cover, and other “tin” on the engine.
I use a piece of round steel with fairly flat ends approximately the size of the round washer on the piece. For instance, the piece shown here is 5/8″ diameter and it works well on MGB timing chain covers.
First picture: Place the round steel in a vice so that it sticks up more than the piece you are working on is deep.
Second picture: Place the piece you are working on upside down over the round steel. The steel now acts as an anvil.
Third picture: Use a lightweight (8 0z) ball peen hammer and tap tap tap until the distortion is flattened. No heavy hitting.
Check the results with a straightedge.