I asked my friend John Ott for his advice on renaming the locomotive General to use on the USMRR Aquia Line. John is the foremost expert I know on early locomotive history. He provided me with a interesting analysis. Here it is.
Well—if it were me, I'd rename your engine Eclipse in a heartbeat. Reasoning follows:
There weren't that many Rogers engines on the Dept. of Virginia lines. None were 2-steam-dome Rogers resembling General except for maybe Warrior, which never made it to Aquia and got rebuilt into the Lt. Gen. Grant in 1864. Osceola was a Rogers, but you already have an Osceola. There were a couple more single-steam-dome Rogers engines bought after the Aquia line was history.
That leaves you with Lion or Eclipse. Lion was an 1862 New Jersey L&M engine with a single steam dome and oval windows in the cab—in fact, it's my theory that the cab of the Lion was used on the rebuilt Lt. Gen. Grant.
That leaves Eclipse. Eclipse was a single-steam-dome engine built in 1862 by Jersey City Locomotive Works. McCallum's end-of-war report is wrong—he has it listed as another New Jersey L&M engine. It was rebuilt and renamed Scout after Aquia, and was later used in North Carolina
So Eclipse is the lesser-known engine that already has one mistake in its record. The name Eclipse also fits the General's nameplate better than Lion. (This is important!) You can just say that Eclipse and Scout were actually two different engines. In this scenario, Eclipse was cannibalized to rebuild Scout, which is why it no longer appeared on McCallum's for-sale list.
Sometimes I think half the fun of building a model railroad is all the rationalization we come up with to hide our compromises.
I like the sound of Eclipse, but Warrior is also a good possibility as its is the right builder but never ran on the Aquia Line.
Note that the US Government sold the engines for more than they paid.