Martin D-1

Martin's original 1 Series model, the D-1 dreadnought, was launched in 1993. At the time it was the first full-size Martin to retail under $1,000, and likewise in sterling here in the UK. Undoubtedly, a major reason for its introduction was as a response to increasingly fierce entry-level competition from other North American makers, not least Taylor with its 410, Guild's D4 and DV52, and Larrivée's D-05.
The spruce/mahogany D-1 was subsequently joined by the rosewood-backed D-1R, two similar auditoriums – the 000-1 and 000-1R – and a pair of mahogany-backed basses, the B-1 and B-1E electro. Other models that appeared during the range's lifetime included a 0000-1 grand auditorium and the DC-1E cutaway dread electro.
Whichever, the all-satin-finish specification involved a solid top and back and laminated sides, necks of either mahogany or Spanish cedar, and A-frame 'X' bracing where the 'A' braces tied into the neck block, which itself had a buttress extension under the top to add support for the upper reaches of the fingerboard.
The 1s were also notable for being the first Martin series to employ its bolt-assisted mortise and tenon neck joint, which was later rolled out to the cheaper Road Series and HPL (High Pressure Laminate) Xs, and the more upmarket 15 and 16 Series.
The bolting aspect has sometimes been misconstrued. The joint is actually glue-bonded, the bolt serving as a clamp while the glue is drying, so the mortise and tenon doesn't act like a dovetail in intrinsically cleaving the neck to the body.
The bolt could be discarded afterwards, but Martin chooses to leave it in situ and there are a couple of spin-off production benefits – first, the bolt hole in the neck block allows the body to be secured tightly in its mould during assembly; second, the heel's threaded insert enables the sprayer to attach a handle to the neck to make the finishing process easier.