The three small apartment buildings along the 900 block of Ashland Avenue date to the early 1900s, and tenants and housing advocates say living conditions there show it, even from the outside. They’ve pointed to deteriorating foundations, water leaks, wobbly decks and open electrical covers. They’ve complained of broken locks, low water pressure, heavy mold, insects, mice and double-hung windows that cannot be locked and slide open from the top …