I've found that, through a combination of preference, price, and availability, that I've become something of an early 1990s K Line collector! Although not quite as refined as some later K Line models, they are nicely painted and detailed, while still being affordable and good runners. I really like the K Line Alco mechanism, it is smooth running and powerful. That I'm already an ALCO guy is a bonus.
Most of my K Line equipment is from the 1990 catalog: I have the complete P&G promotional set, a A-A NYC Alco Set, and NYC Work caboose from that.
From slightly later, I have a Erie A-A Alco set, which if I am correct is from the middle 1990s because it has the close coupling solid couplers between the powered & dummy units, but doesn't have separately fitted handrails.
Finally, from the late 1990s I have the add on NYC Alco B unit with horn.
I'd love to see what you guys have!