Now that it appears S scale is still an option, Here are a couple more thoughts for the OP:
eBay has a few ATSF rolling stock options available, 1 example : https://www.ebay.com/itm/29429...1:g:1kYAAOSw3f1g6LqW
American models also has the Baldwin S12 in ATSF. American Models has other locomotives that are undercoated, so one can custom paint in ATSF road name.
And as someone already pointed out Dave Blume, Pikesville models, has a great inventory of new and used S scale: https://www.americanflyertrain...w_item?item_id=10110
"S" is for Superior,