Revolver_Newb, your revolver is also a .38 Military & Police, but with a 5" barrel, which is generally the least common 4"+ barrel length. This gun later became the Model 10, but this gun predates the 1957 introduction of the model numbering system.
Serial number if 548866, which probably means late 1930s production; more precise build dates from this period are hard to nail down because S&W was using stockpiled frames with no regard to serial number order.
The star probably denotes a factory refinish, although I've more often seen these marks under the stocks (grips), so I'm not certain of this. I have no idea what the number 6130 means; it's not factory-applied (too sloppy), and is likely a police-issue inventory number.
The stocks are not original; they appear to be factory Magna stocks from a late 1950s to early 1960s Model 10 / M&P. These stock sets are actually becoming somewhat sought-after!
Be aware that this gun has the early pivoting or "wing" hammer block rather than the sliding hammer block introduced in 1944 and still in use today. Although arguably better than nothing, the early design is prone to jamming in the disengaged position or breaking off entirely with no externally apparent warning to the shooter. It should not be relied upon unless it's checked frequently for function, and arguably not even then – some argue that these guns should be carried "five-up" with an empty chamber under the hammer as a precaution.
