If a landlord has to make repairs to leased property beyond "normal wear and tear" after tenants move out, labor costs are fair to include. However, if this is truly "normal wear and tear," he shouldn't be deducting anything at all. It's not completely relevant at this point that you added some things to the house during your tenancy: a ceiling fan becomes a "fixture," and the mailbox and washer are items you could've taken with you (and arguably still can).
If I were you, I would send him a certified letter contesting his retention of part of your security deposit. I would also inform him that unless he returns your security deposit in full that you will file an action against him in your local Magisterial District Court. Make sure you have provided him with your new address. If he doesn't return what he's kept, sue him: your story sounds reasonable to me, and I believe it probably will to your local District Judge as well.
If you'd like some assistance filing the suit, feel free to contact me directly. Good luck!
Cary B. Hall, Esquire
Law Offices of Cary B. Hall, L.L.C.
121 East Chestnut Street, Suite 205
Souderton, PA 18964
T: (267) 663-9995
F: (215) 525-4364