The only information I have on Co G, 33rd Tennessee Infantry Regiment is that the company was originally organized in Obion County, TN. It then crossed the Miss River and joined the 1st Division, Missouri State Guard in July, but served only briefly with the Guard before transferring to the Confederate Army. The following is surely your ancestor:Atkinson, Wilford D.: A Pvt in Co G, 1st Inf Regt, 1st Division, MO State Guard, who joined at New Madrid, MO on 25 Jul 1861. Transferred to Confederate Army on 22 Sep 1861 at Camp Belmont, Mississippi County, MO.
I hope that this if some interest to you.