The K-28201 is shown in the online K-Line Legacy Catalog as conventional, not TMCC, with a three position reversing unit and is illustrated as a C&NW model. On the other hand, the K-28841 SKU you give corresponds to Rock Island, not C&NW, E8s that I have recently posted about on this particular forum part. It's 11 threads down from this one under the title "TMCC power board issue - K-Line K-28841".
There is a note on one page of the K-Line Legacy Catalog that says the 28841 set is missing from it and maybe was not cataloged as you say, but it is definitely Rock Island and does have TMCC (of an early variety). I have the original boxes and they are black; these are the engines:
Here is the link to the 28201 legacy catalog listing (although I assume you have already seen this):
http://www.legacykline.com/app...mp;p_oem_sku=K-28201
The note about the missing 28841 and it being a Rock Island set is on a different page (near the bottom):
http://www.legacykline.com/app...p_oem_sku=K2484-0495
If you have C&NW E8 models with TMCC they might have been a K-Line Club or other special run. Or possibly somebody's upgrade, which I think people did with these models if the original K-Line parts failed. A special run seems more likely to me; I have a vague recollection of someone saying somewhere on this Forum that K-Line made such E8s for a Chicagoland club.