Paul has supplied to you before the reference. I believe you will find it in the book I have recommend you read.
M1775 Long guns were M1732 guns without the decoration. They were reintroduced in 1775 when Valliere Junior rather than Gribeauval was in office. Gribeauval adopted them in 1776 so could be called Gribeauval garrison and siege guns. This is what I had referred to in the previous posting were once again cast from 1808 due to the prejudice against some of the Long AnXI gun tubes.