I think the value 1000 should be fine. For discussion purposes, let's convert these leadout times from hexadecimal format to decimal format, and then multiply by 26.25 microseconds.

C760 --> 51040 1340 mSec
B000 --> 45056 1183 mSec
7000 --> 28762   753 mSec
3000 --> 12288   323 mSec
1000 -->   4096   108 mSec
0C18 -->   3096     81 mSec

I guess that if the button is held down for more than the 108 mSec, then the signal may be sent twice by the remote, or perhaps it has its own internal delay.