$51,670.00 in 2012 dollars = $53,177.61 in 2014 dollars. Nominal value in 1973 dollars = $9,992.19, and using the 2,080-hours-per-year rule of thumb works out to $4.80 per hour in 1973, but who made that much back then?
I made $980 month in 1970 so that was about 5.65/hr.