A view of the firebox area of 'AG' 907, although very similar to an H-8, there are some unique features. The firebox lagging extends down further similar to the early in-service H-8's, there is a unique rivet pattern on the mud ring, the injector plumbing is slightly different than that on the H-8 and this air injector arrangement is used only on the 'AG'. The 'AG' is a blend of some old and some new features used during the H-8 production.