So I took a chance that the spring kit from Galloway Precision would fit, I'm happy to say that it does! The instructional video was also very good, though I nearly lost the magazine release detent (it's tiny!) and the trigger return spring was not easy. I also had to make a 1/32" punch out of an old dental tool to take out the tiny roll pin holding in the right side safety lever, which is unique to the K12 Sport.
The trigger was already extremely crisp and the pull was at about 4.5lbs from the factory. I took the time to polish the usual parts while it was in pieces, and now it's even smoother, with the pull around 3.5lbs. Would have liked more, but I expect that'll improve some over time as the gun gets worn in. Sooo... overall I'm pretty pleased with this gun, the now lighter trigger, and especially with my polished and smoother action. Everything about this gun is crisper and cleaner than my 75B, and I shoot them about the same.
I also talked with the Lok Grips folks, and I think the Tanfos will fit, cut short for the magwell. I've debated removing the magwell entirely and going with the medium grips, but TBD on that.
