Help - Destroyed Bag

Normally I clean and condition my own bags but a friend of my husband has recently got into restoration work. According to my hubs he's been doing leather work for a fair while so suggested instead of doing it myself I give him a go. HUGE mistake. I handed over my swagger shoulder bag, only to have it returned looking like this. As silly as it sounds I've spent the last day crying. I know i can't undo whatever he's done but now what could I do to this to make it wearable again? My plan is to clean it like i normally do with my fiebing's saddle soap and recondition the leather but I have no clue what to do about the colour or hardware.