The design comprises the features of shape, pattern and configuration of a combined polishing and grinding pad assembly with abrasive disks, a reinforcement and a pad, as shown and described in the accompanying drawings. The portions shown in stippled lines do not form part of the design. The application consists of two variants, namely Figures 1 to 9, and 12 to 20. The first and second variants have abrasive disks with surfaces having a tapered angle, as seen in Figures 3, 4, 12 and 13. The red-coloured lines shown in the drawings do not constitute a feature of the design. They are included for illustrative purposes only in order to define the boundary of the design. Description of The Drawings: FIG. 1 is a bottom perspective view showing a first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 2 is a bottom elevational view showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 3 is an enlarged fragmentary cross-sectional view, taken along line 3-3 of FIG. 2, showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 4 is an enlarged fragmentary cross-sectional view, taken along line 4-4 of FIG. 2, showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 5 is a top elevational view showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 6 is a side elevational view showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 7 is a side elevational view, opposite Figure 6, showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 8 is a rear elevational view showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 9 is a front elevational view showing the first variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 10 is a bottom perspective view showing a second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 11 is a bottom elevational view showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 12 is an enlarged fragmentary cross-sectional view, taken along line 14-14 of FIG. 11, showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 13 is an enlarged fragmentary cross-sectional view, taken along line 15-15 of FIG. 11, showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad. FIG. 14 is a top elevational view showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 15 is a side elevational view showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 16 is a side elevational view, opposite Figure 15, showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; FIG. 17 is a rear elevational view showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad; and FIG. 18 is a front elevational view showing the second variant of the combined polishing and grinding pad assembly with the abrasive disks, reinforcement and pad.