Mike, yes as you pointed out they would have been at Camp Chase at the same time. Camp Chase was amoung other things a prison camp and also a training camp for new regiments as well as being mustered in and out. It was also a parole camp for Union soldiers who had not yet been exchanged however only during the last half of the War. The official guards at that time period for Camp Chase would have been the 88th Ohio OVI. A few companies from the 37th Iowa were also used at guards at Camp Chase. It would appear that the 128th OVI was being groomed for guard duty for Johnson's Island while training at Camp Chase. It is possible they could have had some "on the job" training for a very brief time at Camp Chase. Interesting question, I'll look today at the National Archives in Washington, DC to see if I see anything about them being used as temporary guards or guard training while in training at Camp Chase. Some of the information at the archives goes into great detail ie the names of the guards on duty and their shifts and passwords and counter passwords for each day etc. From memory I can tell you the password for the guards at Camp Chase for November 24, 1864 was "Atlanta" and the counter password was "Port Hudson"