I've finished the Sunset models K-27 as number 461. It has a Tsunami decoder installed. I painted it with a green boiler just because.... Here's my collection of K-27's: #452, 455, 460, 461 and 463. One of these are not like the others though. As one isn't a brass engine. Which one?
That is a VERY nice collection! I love the variation in the weathering. I have a set of K-27s too, but with one exception they are all Blackstone models. The other one is from MMI when they were in HOn3 scale as well. Blackstone's K-27 models all can be easily recognized by the shape of the coal load that can't be easily altered. So I presume your # 463 is a Blackstone model.
Front to back: #461 Sunset models #460 Westside models #452 Sunset models #455 Westside models And finally #463 Blackstone in plastic. The #460 is the older version with long smokebox and slide valves.