Ed,
No doubt about it -- that is indeed a blue and silver 8020 Santa Fe Alco in the Greenberg photo, and its existence has been a thorn in my side for a long time. It's either a prototype or a factory error, but given the nature of other items in that particular collection, it's likely the former. I've been looking for that particular piece (or one just like it!) for at least 15 years, but the trail goes cold in the mid- to late 1980s.
I think everyone has figured-out the other Santa Fe Alcos, but here's the quick run-down:
8020 Santa Fe: "Warbonnet" red and silver. Offered three different ways -- A-A pair, A-B pair and as a single A. CW, the single A's came in the 6-1193 Sears set in 1971 and the 6-1292 Sears set in 1972. As you mentioned, variations exist with pilots (solid or open), windshields (clear or natural), number boards (solid or separate boards), location of the MPC builder's plate, etc.
8022 Santa Fe: solid blue and yellow. The only official offerings of this piece were a single A in the 6-1195 JCPenney set in 1971, in addition to being offered separately by Penneys in a very scarce mailer box. However, there are at least three packaging variations (two different boxes for single A's and one for an A-A pair) and given the myriad variations of the piece itself (at least four major ones), it had to have been offered some other way. There's a lot of bad information out there on this one, and unfortunately, I think there's more to the story that we don't know.
8351 Santa Fe: "Warbonnet" blue and silver. Primarily available in the cataloged 6-1383 Santa Fe Freight sets, but was also available in the 6-1393/1394 Sears sets in 1973 and 1974. Lastly, Sears offered the unit separately 1974, packaged in a very scarce mailer box.
Oddballs:
For some reason, Lionel experimented with sprayed versus hot stamped lettering on a few of the 8020's. Apparently, only 100 pieces were produced. Very strange.
![8020b 8020b](https://ogrforum.ogaugerr.com/fileSendAction/fcType/0/fcOid/2415514336567652/filePointer/3400749731616800/fodoid/3400749731616772/imageType/MEDIUM/inlineImage/true/8020b.jpg)
Here's an 8022 stamped for 8020.
![IMG_2940 IMG_2940](https://ogrforum.ogaugerr.com/fileSendAction/fcType/0/fcOid/2415514336567652/filePointer/3400749731616799/fodoid/3400749731616771/imageType/MEDIUM/inlineImage/true/IMG_2940.jpg)
Oops.
![IMG_2942 IMG_2942](https://ogrforum.ogaugerr.com/fileSendAction/fcType/0/fcOid/2415514336567652/filePointer/3400749731616798/fodoid/3400749731616770/imageType/MEDIUM/inlineImage/true/IMG_2942.jpg)
Enjoy!
Todd