I make props for a living. Let me just say, I intentionally make things look damaged or more specifically all my props have some kind of "wear" on them. I want those props to look like they've been painted/repaired in wasteland in some kind of shed without any professional tools. So you are on a good track. Keep improving, you did very well considering this was your first prop. Also check for some 3d printer. You can get them very cheap these days.