No need to apologize to me.
I am personally unable to absolutely confirm the accuracy of either your book citation or the Official Records. For all I know, they both could be wrong. However, in many cases, the Official Records have been proven to be an accurate source.
For what it is worth, I have seen other books that prematurely assigned the 29th to Corse's brigade [seemingly by mistake] in anticipation of what appears to be most likely the actual time frame.
My post was merely to provide a set of "Official Records" facts, regarding the time frame that the 29th Virginia may have actually joined Corse's brigade.
I think you will discover, in most any source, that the 29th Virginia is not in Corse's brigade for the order of battle for the December battle of Fredericksburg. That should pretty well eliminate any possiblility that this regiment was in this brigade during December.
The Official Records, [for whatever value you may attribute to them], indicate the presence of the 29th Virginia with Humphrey Marshall in September of 1862, and then again on December 15, 1862, when Marshall advises the War Dept. that he is only now sending this regiment to Richmond.
And, Corse's brigade can be tracked to find that it was not in the same area of the 29th Virginia until late February or March.
Many are the contradictions in Civil War records, and that is one reason we all continue our research.
BTW, back in the day, I bounced back and forth from Corporal to Lance Corporal, so Sir is not necessary.
Best of luck in unraveling this situation.