Started with the following wounds:

cuts and bruises about the chest area, cuts and bruises about the abdomen

25 mana CF to the chest:

some minor abrasions to the chest, cuts and bruises about the abdomen

40 mana CF to the abdomen:

some minor abrasions to the chest, some minor abrasions to the abdomen

Couldn't really check internals, but was rather expecting a bit more from the added mana. Does extra mana into the spell provide some other benefit?

>Was the body part you healed yourself with damaged on the mob you were using?

No. I target head/neck/back as appropriate to heal down.