If I were to build a solid Karn based deck in Vintage, I would start with:
4 Sai, Master Thoptist
2-3 Skull clamp
Restricted Blue/Artifact stuff (tinkerbot/tv optional)
And go from there. Obv about infinite splashes after this point, but I'd use that as the core, and see what you have room for from there. Would be glad to discuss this tho. Keep this updated. Thanks!