Your Bryston amp puts out what, 300 watts of power? My HH Scott 299C puts out 30 watts per channel and it could make your ears bleed with Cornwalls at the 7 position on the volume knob. But that's tubes for you!
The LK-72 is the kit version of the 299D, not the 299C. As such it would be most excellent with your Cornwalls as my son has the 299D and a pair of Cornscalas. Hard to beat with systems costing $30,000 and up.