Neil You do come up with some good ones.... Maybe this can help.

WR Perkins as listed on 1 muster card as being in 1st and 4th MO Infantry caught my eye as it listed his enlistment place as Alton. Makes no sense. So who is he? A little further digging led me to WR then William then Wilson Perkins of Kemper Co Mississippi. He was a Private in Co I 40th Mississippi Inf. Appears he was absent without leave eventually listed as captured on retreat from Iuka, listed as Price's Division (thus the card transcriber has a Missouri connection) and the 1st and 4th Missouri was consolidated by combining Co I of the 4th Missouri with several remnants of the 1st Missouri. Wilson AKA William (may be two different people) then appears to be captured in 1864 at Chattahootchie.

So take a look at WR Perkins of Mississippi who is listed as died in hospital March 1863.

Would not be the first transcription error of Miss to Missouri I've run across.

Then there is a WC Perkins (MO) that appears to have a set of cards nearly identical to WR Perkins (MO).

I'll dig into the census records to see what I can find.
JJR