Thank you VaNana for the clear photo showing the backside detail of your Tongue & Wreath (T&W) buckle piece. We can now see without doubt that this is entirely a cast brass buckle tongue. Also, the recessed center with a raised rim is a distinct feature that is not seen as commonly as other styles on the back of these buckles. Among the collecting community, this style of recessed back on T&W buckle tongues, is generally referred to as the "Bottle Cap" style cast buckle, since the back resembles a cap.
Additionally of note, your example shows a benchmark on the locking tab. This one appears to be either VII or VIII (Roman numerals 7 or 8). In most all cases where there are benchmark numerals on the backs of cast brass T&W buckles, these same marks will be seen on both the tongue and wreath portion. These markings apparently facilitated the correct matching of cast buckle halves, during the manufacturing process. Originally the thought among some collectors was that these marks may have been cut (or in some cases stamped), into the buckle backs after casting. Careful study though, comparing similar tongues and wreaths that were obviously cast from the same mold, shows that in most all cases the benchmark numbers were in fact in the mold, as the details and positioning is exactly the same on repeat examples.
The following photo shows three cast Eagle buckle tongues, featuring an upright spread-wing eagle with a breast shield, surrounded by 27 stars. These buckles date from about the time of the Mexican American War, through the early 1850's. Whether the number of stars is relevant to the number of American states at the time these buckles were originally designed, or merely a random number of stars that simply fit the design, is certainly speculative. If in fact the number of stars is representative of the number of states, these buckles would date from 1845 or after, when our 27th state Florida was admitted to the union. The lower left buckle shows the "Bottle Cap" style back, similar to what we see on the back of VaNana's example. On the back of the belt loop of the buckle on the lower right, there is a benchmark II.
CC Hunter