I so happen to have the same old vintage tube amp. You can do more with those 30 watts than you might think as they will push some very difficult speaker loads. I have an acquaintance in DC that uses a Scott 222 with 22 watts per side to push a pair of Magneplanar 3.6Rs. Not at high levels necessarily, but at volumes that satisfy his listening needs.
The point I make is that they will push some inefficient and power hungry speakers better than you might anticipate.
Their strong point from what I can gather from many is that they do very well with efficient 8 Ohm speakers like the old AR 3As, JBLs, Advent, POLK, Boston Acoustic, Paradigm. I am using mine to push a pair of vintage JBL 150A's and they are very effective. They marry nicely with the JBL 12" woofer and passive radiator design.
They also do justice to my MG IIIAs. They do a lovely job for me with both speakers given their minimal power output.
I have also heard that they make a pair of B&W 604s sing beautifully. I would like to try that pairing myself. Best of luck in your endeavor. Tell me how it ends up for you. If you would share, what output tubes and drivers are you employing for your LK72? Thanks.