Lot
5133 
Ecuador, 1865, 1r Chrome Yellow, horizontal strip of 5 on piece (positions 40-44), red fancy "P.I." cancels of Quito, full margins, pre-use tear affecting first stamp, Very Fine appearance, ex-Olgieser. Scott No. 4 Estimate $750 - 1,000.
The P.I. stands for "Porte Interno" or internal fee. It is believed that this cancellation was produced in France and was introduced in 1870.