The 354 absorbance is small compared to the oligo A260 but what you have is reasonable. You can quantify the number of oligos attached using the extinction coefficient of the oligo (from the product data sheet, molar extinction coefficient at A354 is 29,000). Note the protein does not contribute much to the A260 so it can be ignored unless you want to be very accurate. Determine the protein concentration with a BCA assay. With those numbers, you can accurately determine the number of oligos/antibody.