One reason for the small number of surviving letters is that Handel did not hold any office that would require the collecting and saving of his records and writings.
All remaining letters and writings maintain a uniformly polite tone.
A typical complimentary closing (used in many letters) was: "Sr, Your most obliged and most humble servant, GEORGE FRIDERIC HANDEL".
The letter dated 30 September 1749 is reproduced in the pdf document cited at its entry below.
[2] Note that where quotes have been supplied from the letters, the original spelling, punctuation and capitalisations have been reproduced.