County Probate Records

Estimated Real Property Values in 1983?

I have a will that’s never been probated, however, I’m hoping to do a small estate transfer of real property – year of death was 1983. A real estate agent researched the value of the home and found that the MLS association only had records going back to 1996. She performed an analysis using the 1996 value and back-tracked to 1983 and provided me the analysis and two estimated values on her company letterhead. Will this letter be acceptable to the court? She said that the only other thing I would be able to do is the go the the county recorder’s office and lookup sales for 1983 which would be a very tedious task.

Thanks

The county Tax Assessors office would have that information