Where can i find a map of nashville tn before percy priest lake and i-40? like 1950-ish...?

You can look in Ebay; I've seen people posting vintage maps there. Another option is to put an ad on Craigslist.org, Nashville, Tennessee area. When someone answers your ad, tell them to post it on Ebay, so U've got Ebay's buyer protection guarantee to protect you from fraud.