From a zip code database:
Here are all 29 cities in the U.S. with the initials JC. (Junction City AR is adjacent to Junction City LA - they appear to be the same city, divided by a state line). From what I can gather, the cities marked with the triple asterisks have a 400 block of Main Street (or in one case, Main Avenue), although not all have the exact address 468. I didn't see too many three story buildings in any of these locations.
Using Google earth, it is difficult to determine if an exact address actually exists. And of course, an address (or three-story building) existing prior to 1985 may not exist today.
Jacks Creek, Tennessee
Jackson Center, Ohio
Jackson Center, Pennsylvania
Jacobs Creek, Pennsylvania
James City, Pennsylvania
James Creek, Pennsylvania
Java Center, New York
Jefferson City, Missouri ***
Jefferson City, Montana
Jefferson City, Tennessee ***
Jeffrey City, Wyoming
Jerry City, Ohio ***
Jersey City, New Jersey
Jewett City, Connecticut ***
Johnson City, New York ***
Johnson City, Tennessee ***
Johnson City, Texas ***
Johnson Creek, Wisconsin
Johnston City, Illinois *** (Main Ave)
Joseph City, Arizona
Junction City, Arkansas ***
Junction City, California
Junction City, Georgia
Junction City, Kansas
Junction City, Kentucky
Junction City, Louisiana ***
Junction City, Ohio ***
Junction City, Oregon
Junction City, Wisconsin ***
ETA: Although it appears to be "J.C.", it might be "T.C." with a slip of the pen at the bottom of the "T". If that's the case, there are 36 cities with the initials "T.C."
Tabor City, NC
Tahoe City, CA
Tawas City, MI
Tell City, IN
Temple City, CA
Tennessee Colony, TX
Terra Ceia, FL
Texas City, TX
The Colony, TX
Thetford Center, VT
Tiff City, MO
Tioga Center, NY
Tipp City, OH
Tomkins Cove, NY
Tower City, ND
Tower City, PA
Town Creek, AL
Trabuco Canyon, CA
Tracy City, TN
Trail City, SD
Trapper Creek, AK
Traverse City, MI
Tremont City, OH
Trinity Center, CA
Trout Creek, MI
Trout Creek, MT
Trout Creek, NY
Truth or Consequences, NM
Tuba City, AZ
Tunnel City, WI
Turkey City, PA
Turkey Creek, LA
Turner Center, ME
Turtle Creek, PA
Turtle Creek, WV
Twin City, GA