This series of volumes constitutes a record of the costs involved for work done and materials used by the company. Along with details of costs in wages and costs for materials other information can be extracted including, general expenses, selling price of order, details of whether the order constituted a loss or profit, cost before delivery, when order was delivered and whether any expenses were incurred.

For all volumes except 619 there exists an index and an analysis of the index. The indexes are ordered by stock number. For each stock number there is a description of what the order is and who it is for, the page number of the volume where details appear is given as the quantity of the items ordered. The analysis of the index sheets split the index entries into different categories such as loco engines, tenders, cylinders, duplicates, crank axles tools etc.