A private recording using the Crosley Home Recorder, this piece was a regular feature of Barrios' live performances. It was recorder over several sides and, in the absence of any written source, it is imposible to say whether or not we have the complete piece or even be sure that the various sections appear in the order Barrios  would have played them.
The snare drum effect starting at bar 19 is achieved by crossing the fifth and sixth  strings at the ninth fret, and tambora starting at bar 103 is unusual in the Barrios  appears to be striking single string rather than a whole chord.
From bar 135 onwards, the snare drum effect moves to the fifth fret.
In the passage starting at bar 148, the acciaccaturas are struck in the normal way and followed by natural harmonics as shown. The pizzicato from bar 182 requires the damping of the bass string only.
The sequences from bar 233-244 has been notated as Barrios played it, but is irregular content suggest that this may be only an approximation of the was intended.