This may be a late reply to your posting but I will try. I descend from the Halbert's that came to Lincoln Co., TN also. In my Halbert book there is a Martin Halbert that descends from John Halbert that came to LCT in very early 1800, like 1808, from Surry and Stokes Counties( Stokes was divided from Surry). I have Martin as being the 6th child of John and my William being the 7th child of John. William is the one that I descend from and it states that on the 1930 census Martin was living next door to his brother William (mine) and that Martin was between 40-50 years of age. And it states that a letter from William Hay Halbert M. D. said Martin's descendants lived in AR about 25 miles E. of Texarkana.
I don't know if any of that is helpful, but there it is. My tree book doesn't say any thing else on Martin. Hope it helps. Gerald