I have a working programmed atmega 328. I am not sure which iteration of my arduino code I used. Is there a way to tell?
Nope. You could copy the code from it using avrdude commands, but that just gets you the .hex code the chip is running, with no comments from your original sketch or history of IDE that it was created with.
If you view the hex code using a hex viewer, you might recognize some text if you had Serial.print statements with text in it.