Windoze 7 may not like the post box...............
Frank I need to give you one of my plates with a stack of stickers! Who knows what's there or if it is worth anything but I would split any thing you make off the stickers with you!
Waaaay too early for a 64.5 Mustang; J series are likely change-over plates in 1963 when Cali went from black on orange to orange on black.
J could be perfectly fine for a 64.5.Frank
Frank is correct, my brother's early '65 (built Sept '64) starts with JKN.