So what Omega knot Clint64 use in your brush? I really like the aesthetics of the blonde boat knots in these handles... So much that I got an Omega 49 for this purpose but the knot appears to be way too big.
Mark sent me a Omega 10066 to use and it was much easier to install in the 400. For reference below is my 400 unmarked with a Omega 49. While the 49 is much easier to remove from the old plastic handle, it requires some that the opening be enlarged to the max. The 10066 was much harder to remove the knot but it did not require the opening to modified in any way.