I love the irony of ST IV, where the distinctive panels above of the Klingon library computer, used by resurrected-Spock, to research whales, are the same panels used in the reactor room, where Spock died two movies earlier.
The room on the Klingon ship in Trek IV where they ID the sounds of the humpback whales is a re-dress of the dilithium chamber set from Trek II. You can recognize the monitors.
Actually, the monitors you're both referring to were originally from the Klingon bridge set in TMP. You can sort of see them along the back wall here:
http://movies.trekcore.com/gallery/albums/tmphd/tmphd0031.jpg
http://movies.trekcore.com/gallery/albums/tmphd/tmphd0032.jpg
Although they're clearest on the Klingon bridge plans in the David Kimble/Lee Cole TMP blueprint set. The hexagonal shape of the monitors is the giveaway that they're meant to be a Klingon design.
Now, it does seem to be true that the
Bounty science lab is a redress of the TWOK reactor chamber, since it has the same basic configuration overall, not just the monitors:
http://movies.trekcore.com/gallery/albums/twok/ch14/twok1105.jpg
http://movies.trekcore.com/gallery/albums/tvh/ch5/tvh0236.jpg
But the monitors in the reactor room were cannibalized from the TMP
Amar bridge, so TVH essentially restored them to their original function as Klingon equipment.