Mandolin Tone-Gard. $75.
The Tone-Gard by Tony Pires is an ingenious device that fits on the back of a standard acoustic mandolin and creates a gap between the player's abodomen and the back of the instrument, mitigating any damping effect that said abdomen might have on said back.
     Here is a somewhat used Tone-Gard bearing the initials SJM. This would be perfect for you if those are your initials, or if they say something else about you, or even if they merely stand for Sorry, Just Mandolin.
     This one is slightly used. New Tone-Gards cost $89 and customized ones are no longer made. Call 425/772-0231 or for more information. $75 plus shipping.