From reading your information, I think you are not looking at this as two separate tax situations.

First is what happened when the Partnership was in business - the land sale.  The K-1 shows the gain. 
Enter the K1 to partners return accordingly.

Second is the liquidation of the Partnership.  Determine the partner's basis.  Determine the amount liquidated - was there anything after the land sale money was distributed?.  

Remember the land sale is a done deal on the K1.