This is an OMC Cobra Stern Drive  3.2 Diesel Parts Catalog part # 987486 printed 1992.  It is the manufactures publication not a copy.  This shows all the part diagrams with the reference numbers for the parts.  See the second picture for a typical page.  If you have one of these it would be invaluable for referencing the assembly of the components and for obtaining the correct part number so that you can find the needed part.  It  will save you money and time when used as a refrence this was designed to be used buy the parts counter in a marine repair shop.  This is much more valuable than an owners manual which just has basic sepecifications and other basic operation information.  This is a very rare item since not many of these were produced.