To long and wordy just a simple it violates the 2nd amendment and we will not comply would have worked better.
I think that should be the followup but IMO the letter was just right. Remember the DoI and how it lays out a 'long train of abuses and usurpations' and counsels that "...a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation." That long letter leaves them no excuse that they were not "...Petitioned for Redress in the most humble terms:..."