A D-18 GE vs. a 1936 D-18

36D18_saddle.jpg (33601 bytes) Here's a shot of saddle locations- the bass contact point is indicated by the penciled line just past 12 7/8".  The zero end of this yardstick is resting right in the middle of the 12th fret and I took these measurements from an actual guitar that actually played in tune. The low E on this 36 intonates perfectly, w/out resorting to a razor sharp rear edge. Now check out the location of the GE's saddle.  It's a little too far foward.  Note also the location of the bridge pins. The '36 is sitting right between 13 1/8 and 13 2/8, while the GE is just barely behind the 1/8 mark. Not all GE's are this far off, but use this as a check. GED18_saddle_location.jpg (30698 bytes)

Here's a couple of shots of the headstocks.  Notice the difference in the tuner buttons.  The GE has Waverlies, which are nice tuners, but lack the scalloped edges of the real Grovers.  Also notice the rounded tops of the Waverles, versus the flat tops of the Grovers.  The decals look pretty comparable.

 [I'm informed that this '36 has non-original tuners that probably were added in the 40's]

36D18_braces.jpg (43515 bytes) Interior shots: notice the low rounded back braces of the '36 versus the tall braces of the GE.  I've shaved the back braces down on the GE's and gotten a richer, bassier sound.  I wouldn't call this a "big deal", just pointing out some differences.  Paper label in the GE, of course. D18GE_braces.jpg (45837 bytes)
  This isn't a GE, but the GE has the same setup- wooden block covering the truss rod nut. '36 has a non-adjustable T-bar.  I'd consider both of these to be "Good Things".  The GE has a popsicle brace, the '36 did not originally, but had a short brace added due to damage.  I'm not a big fan of the popsicle.
This is not the '36, but it shows the same thing- the tuner hole in old Martins was drilled to fit the tuner shaft.  On the GE, the hole is larger and the shaft does not make contact with the peghead wood.
36D18_pickguard.jpg (52337 bytes) The '36 sure looks a lot browner in this picture!  I'm not sure if that's age or lighting.
36D18_back.jpg (81086 bytes) Not a whole to say here- the GE has an accurate looking backstrip and the wood is certainly very nice.  The '36 has been played a little more!
36D18top.jpg (80670 bytes) Same as above!  The GE needs to be played for about 60 years.  There's more black on the GE, but that's probably just an individual thing.
Overall shots. These show how similar the two guitars really look.  Up close, there's more red in the GE 'burst, but I suspect that will fade out over time.

Summary of main structural differences:

That's about it.  I'm not considering bridge pin, saddle, or nut material because these are easily changed and very, very few old Martins still have the original stuff anyway.

Overall conclusions?  The GE series are decent copies of the originals.  There are many places where they differ, but many of these (back braces, popsicle brace, pickguard, tuner holes, bridge pin holes, etc.) can easily be modified to more match the originals.  Earlier GE's sometimes had the "triple-whammy" of a low action, high saddle, and lots of neck relief which made it impossible to raise the action w/out giving the guitar an extremely tall saddle.  For the past 3 years or so, though, the GE's I've been getting in for setup have had excellent geometry.  Sound-wise I've found the GE's to be pretty close to the originals, given that they don't have 60-ish years of playing.  We've A/B'ed modified GE's against prewars and have often actually preferred the GE's in some cases.  In those cases the old one sounded dull and boomy while the GE had a crisp sparkle to the tone. 

I like the GE's a lot and the sunburst one in these photo is my personal guitar.  That's a pretty good recommendation, I think!  On mine (I had a natural, too) I run the stock ivory nut, a bone saddle for more bite, and black water buffalo pins in a slotted bridge.  I remove the popsicle brace but leave the truss rod cover in place, shave the rear 2 back braces, and plug the oversize tuner holes.  I put a 30's style Tortis pickguard on. And then I play!