138 - T20, T14, D18
153 - T20, T19, D18
150 - T20, T18, D18
147 - T20, T17, D18
141 - T20, T15, D18
156 - T20, T20, D18
Martin D18.
no
Treble 17. Double top. Then the bull out. Treble 17. Treble 20. Double 15. T20-T19-D12 T20-T15-D18 T17-T18-D18
66 - T10, D18
According to the Martin Guitar website the guitar with that serial number was made in 1985.
D28 and D18 are likely references to two models of dreadnought guitars the CF Martin company has put out. D18 being the less expensive of the two...and D28 being a step up with significantly more exotic woods used for the back and sides. the HD28 takes both models a step further by using herringbone purfling around the edge of the guitar.