You are absolutely correct. Colston had a very short term of service in command of the 3rd Brigade. Earlier in 1863 it was under the command of Warren, even though technically the brigade belonged to Taliaferro, and in late May General 'Maryland' Steuart was awarded the command.
I was hoping someone had access to some records that could pinpoint Dudley's service. Guess I will have to happy with the March-May time-frame.
Thanks for the information you provided in both messages.