• 18.039 in their throats.

I’ll definitely check for any singular throat in the work!  I seem to recall in Chapter 5…

• 12.011 began to throb

Yes, indeed, OED lists it as “throe”, usually used plurally.

• 14.024 His last throes splintered it to sparks

“throe | throw(e, n.” OED Online. Oxford University Press, June 2015. Web. 22 June 2015.

• 01.102 This was made by Thror,
• 01.122 in my grandfather Thror’s time
• 01.126 Your grandfather Thror was killed,
• 07.054 son of Thror,
• 10.008 Thror and Thrain of the race of Durin,
• 10.008 Some sang too that Thror
• 10.020 son of Thror King under the Mountain!’
• 10.029 son of Thror King under the Mountain!
• 10.034 that it was Thror’s grandson
• 10.034 not Thror himself that had come back
• 10.044 O Thorin Thrain’s son Thror’s son!’
• 12.035 with the whole hoard of Thror on my back?
• 12.096 the great golden cup of Thror,
• 13.045 This is the great chamber of Thror,’
• 14.041 For he too had not forgotten the legend of the wealth of Thror.
• 15.009 and the people of Thror;
• 15.019 and the legend of the wealth of Thror has not lost

• 02.054 before they throttled him.
• 05.012 He just throttled them from behind,

• 03.044 when the thrush knocks,” read Elrond,
• 11.030 in the grass was an enormous thrush,
• 11.032 The old thrush,
• 12.082 The old thrush was sitting
• 12.082 and threw it at the thrush,
• 12.084 The thrushes are good
• 12.090 All the while they talked the thrush listened,
• 12.101 the thrush’s stone,
• 14.019 but it was only an old thrush.
• 15.003 There is that old thrush again!’
• 15.004 Sure enough the old thrush was there,
• 15.011 than the old thrush gave a loud call,
• 15.013 and back came the thrush;
• 15.017 The thrush,

• 06.080 as he came hurtling down like a thunderbolt.
• 12.072 the shock of my tail a thunderbolt,

• 04.004 until one day they met a thunderstorm
• 04.004 – more than a thunderstorm,
• 04.004 You know how terrific a really big thunderstorm can be
• 04.004 especially at times when two great thunderstorms meet

• 06.029 A very ticklish business,

• 02.113 among an untidy litter of plunder,
• 04.025 though they are usually untidy