How are the specimens labeled? The dredging sites were all given a DR.xxxx identifier, and if those are still on the specimens, matching them would be much easier. If it was only a date, it would still be useful. Otherwise, I suspect that matching the specimens to where they were found would be very difficult...
The PTB have previously said they aren't currently interested in the sea floor temperatures, especially as they have already been published in the dredging records, and so are actually transcribed! They occasionally turn up in the Albatross' logs.
Edit: Hopefully I'm not sounding like too much of a downer, Janet! It's actually quite nice that someone else is interested in all this stuff I've been looking at for a while
The notebooks you found do indeed to seem to be the ones I've found before. The reports from the Fisheries Commission are essentially typed up summaries of those, and are somewhat easier to read - though perhaps there's some information in there that wasn't copied over.