Completing proof of claim for GM

Hello, I am trying to complete a proof of claim for litigation involving GM. I purchased a bond within the specified time frame but am not sure how to complete part of the form. Under the Purchases and Sales section, where it asks for all purchases, (I only have one), It asks for "description of bonds/notes". Do I just put in how many shares of the bond I purchased? It asks for "principal amount", and I assume that would be what I paid for the bond minus the accrued interest.(?). Then it asks for "purchase price per $1000 of principal amount" and the next box is "Aggregate cost". I assume the first box means the price paid per 1000 shares which was 104.995, although with bonds, I know you multiply that price by 40 and not 4000 to get the actual total cost, and the Aggregate Cost would be the total of what I paid. Would the Aggregate Cost be the same as the Principal Amount (minus taxes, fees and commissions)? Thanks for any help. I am not real knowledgeable about bonds. Barbara L.