Congratulations, these are among the best and most versatile (and sought after) mandolins around. Gibson made several models of A styles, but they differ primarily in cosmetics rather than wood or construction. My 1920 A is serial number 68510, so yours is probably a couple of years younger. Do have it checked over by a competent repairman, especially if it has been sitting for some years without being played. These are selling for $750 to $1200 depending on condition and sound, so it's worth spending a bit to make sure it's in good shape.

Sandy