Here, from Fender's own site, the two woods discussed http://www.fender.com/news/tech-talk-ash-and-alder/ and in summary, for the period, it'd likely be red alder for a coloured finish and white ash for clear/natural finishes.
Note that an ash body will weigh more than alder:
White Ash average dried weight = 42 lbs/ft[sup]3[/sup] (see http://www.wood-database.com/lumber-identification/hardwoods/white-ash/ for more data)
Red Alder average dried weight = 28 lbs/ft[sup]3[/sup] (see http://www.wood-database.com/lumber-identification/hardwoods/red-alder/ for more data).