Basis will be fair market value at the date of death which is probably about you sold the items for.
I assume you are doing the 1041 Estate return.
Go to Income tab
go to Investments
Stocks, Bonds other.
Note this will be long-term gain or loss.
Check box E Basis not reported.
You will enter the sales price, sale date, cost, and purchase date (I would use one date) and also lump things together as Household Goods.
