Save that dipstick, Jim, it may become a rare collector's item! Kinda like a stamp printed upside down.
You can find the right dipstick occasionally on ebay, but other than that you'll need to haunt the boneyards. I'd try Desert Valley Auto Parts (
http://www.dvap.com) as I know they have several 64 Lemans's. Call them at 1-800-905-8024.
Bill