Schedule L is supposed to be reported on the tax basis. The fact that your schedule L shows an ending capital of about $800 might indicate you have that as unrecovered tax basis and thus have suffered a capital loss of that amount. Such items do occur on private partnership's because at the original formation, certain expenses (usually syndication fees) had to be capitalized and are never deductible by the partnership.
Did you receive any instructions with the K-1?
The only way to know for sure would be to start with that $12,500 and then add each year's profit, subtract each year's loss and distributions as shown in part III. The use of the tax basis for Schedule L was not always required. Sometimes, the promoters reflected in income on L their assessment of the appreciation of the property, making it wildly inaccurate to use for tax purposes.
Box 10 is probably the loss from the disposition of the property. Box 11 can be multiple items there should be a letter to go with it to identify it for tax purposes.
