I looked at the pics you posted of your snake and the missing scales. The thing is that there is no way of knowing how long it may take. every animal heals differently so that may heal in one or two sheds and then it may heal in a year. Also You might need to get use to the idea that the scales might not come back now it will heal and be far less visible as the animal grows but there is a chance that your snake may just have a scar there and no scales. Only time and your loving care will tell.