Retroactive Gift Tax Filing to Decrease Capital Gains

Hi,
 
My dad had a property he bought in 1992 for $120K. He transferred the deed to my brother in 2018 for $1. He did not file a form 709 gift tax return. Our family is about to sell the property for $320K in 2020
 
However, my mom has -$200K in capital loss for 2020. Can we transfer the deed from my brother to her name, so we can apply the -$200K capital loss to the $200K capital gain from the property sale?
 
I believe the IRS would want us to substantiate the $120K cost basis for the property being sold, so we would have to show the initial $120K deed transfer from my dad in 1992, and then would we have to retroactively file a form 709 for my dad to my brother, and another form 709 from my brother to my mom?
 
Just want to make sure I am not doing anything illegal or anything that would trigger an audit. I believe everything I am doing is legitimate, and there are no laws against transferring assets to another person to apply capital losses to capital gains but want to ask an expert before I transfer the deed.
 
Thank You!