A rigorous theoretical investigation has been carried out to study the properties of obliquely propagating dust-acoustic (DA) waves in an electron depleted magnetized dusty plasma system containing nonextensive q-distributed ions and mobile positively charged, as well as negatively charged dust particles. The reductive perturbation technique is employed to derive the modified Korteweg-de Vries (mK-dV) equation to analyze solitary waves (SWs) and the standard Gardner (SG) equation to analyze SWs and double layers (DLs) solution. The basic features (viz., amplitude, polarity, speed, width, etc.) of the DA mK-dV SWs, SG SWs, and DLs are examined. The comparison between mK-dV SWs and SG SWs is also made. It is seen that the amplitude, polarity, speed, width of such DA SWs, and DLs are significantly modified by the presence of nonextensive ions, external magnetic field, and obliquity angle (the angle between the external magnetic field and wave propagation). The results of our present investigation may be useful for understanding the nonlinear wave propagation in various interstellar space plasma environments where positive and negative dust particles are available. (C) 2016 AIP Publishing LLC.