If you just need a basic idea of what the home was worth in 1974 you could try to speak to a Realtor in The neighborhood. If you need the info for the courts or to settle an estate, I would first try a Local Realtor and the an appraiser.
Hello Melody. This is a job for a licensed appraiser. The appraiser will have to go back and research sales that occurred back in 1974. I would check with a forensic accountant to get a referral to an appraiser who may be able to help you with that. I am assuming you need this information to determine value as of a certain date for tax purposes or are you just curious.