I can't help but chime in with my ultimate dream locomotive for the wish list here... Not a Pennsy K4, but a CB&Q K4 - a ten wheeler - in particular locomotive #710 and perhaps an alternate variation of one of her other surviving sisters. The K4 engines were built in the B&MR shops in Havelock, Nebraska (northeast Lincoln) only a mile or so from where I grew up, and #710 remains on display in downtown Lincoln today. Two other sisters survive, #719 in Alliance, NE and #915 in Council Bluffs, IA. I actually created train simulator models of all 3 engines a few years ago but would love having a 3 rail O scale version to join the 3rd rail CB&Q Hudson and Mikado I already have. They'd be nice medium / small size engines for branch line duty on smaller layouts. If one were ever made getting at least one wouldn't even be a matter of discussion - I'd have to have it