1924 Gibson MB-3 "Trap Door" Banjo-Mandolin

This is the best-preserved Gibson banjo-mando that's been through so far. It's lived in its original hard case its entire life and seems to be entirely-original except for a missing pickguard (though the brackets that once held the pickguard are still there). It comes from an instrument-collector's estate and is here to move on out.

The smaller 9" rim size and heavy-duty construction lend this little guy a leapy, direct voice that cuts and slices just-so. Its trap-door resonator, however, allows you to control the tone from crisp/open to a mellower, quieter closed-back setting -- so some tonal control is definitely at your command if you don't want to be the guy at the jam who's slapping everyone's ears silly.

Work included: a fret level/dress, bridge compensation, general cleaning, and a good setup. The neck is straight and it plays on-the-dot with hair-under 1/16" action at the 12th fret, strung with 32w, 20w, 13, 9 gauges (the GHS A240 set). These "ultra-light" strings are ideal for banjo-mandolin as they remove the "woof" effect of anything heavier.

Scale length: 13 7/8"
Nut width: 1 1/16"
String spacing at nut: 29/32"
String spacing at bridge: 1 5/8"

Head diameter: 9" with original skin head

Side depth: 3"

Rim wood: ply maple
Neck wood: maple (dark stain)
Fretboard: ebony

Neck shape: flat board with medium to deep C/V shape

Bridge: maple/ebony and lightly compensated

Nut: original bone

Tonering type: hollow hoop

Weight: 5lb 2oz

Condition notes: it's clean save the usual fine weather-check all over in the finish. It does have what appear to be factory-covered-up extra tuner holes drilled at the headstock. I have pics lower in the post to show it more closely, but it seems like someone drilled the holes in the wrong place (oops!) at the factory and they patched it up in production as the headstock has the same original finish throughout. It's pretty wild, really! The bridge is a replacement and it may be missing an original pickguard and bracket, but otherwise the instrument is all-original.

I love this headstock shape. Gibson headstock got plainer and plainer over the years, but these "stepped" designs are real pleasing to the eyes.

It has pearl face dots and side dots as well.

The single "hoop" flange is a great design element on these old trap door Gibsons. It's comfortable against the leg and negates the need for a bunch of individual shoes that inevitably need to be tightened now and then.

Here's the trap-door adjuster mechanism -- one side twists to lock closed over the coordinator rod and one side has a spring-clip bracket to hold it away from the rod.

During setup I add a bit of foam dampening under the tailpiece cover and fretboard extension to mute random unwanted overtones.

Here's the original hard case (in good shape) with its collection of antique string packets. The blue-background Gibson string packs are ones I don't see very often.

Alright -- here's a pic with one of the tuner plates off. Note how close to the side of the headstock the second set of holes (the plugged ones) were drilled. I'm assuming this was a mistake at the factory that was rectified by plugging and finishing-over. There's no way that any sort of mandolin plates would've fit on that headstock with them that close to the edge.

The factory order number -- 11109A -- correlates to 1924, per Spann's Guide to Gibson.

Coordinator rods make accurate (and on-the-fly) setup adjustments very easy.

Here's the trap door resonator off -- and with its Patent-Applied-For mark showing.