Parents deeded home (1966) in GA to me/brother in 08 but lived there til death in May 22. Not a life estate. No appraisal in 08. What is basis? We made improvements.

Parents bought house for $13,500 in 66 and we just sold house in July 22 for $118,000.  Made $25K in improvements since 08.  Without life estate afraid can't step up basis to 08.  What about gifting property?  In 08 gift amount was $12K per person for property.  We split proceeds from sale.  House was paid for.  We helped with or paid for improvements over years.  Doesn't seem fair to pay capital gains tax on gross proceeds $107,500.