SF : characters include a Mouse and a Librarian

I have been searching for this one for literally years : all I remember is that it was set (I think!) on a dying sun, cool enough to support life. There is a mixed rag-bag of characters including (I think!) a talking mouse and a Librarian.

I have a vague memory of a title, but it is not right as I have Googled and nothing suitable comes up : "Cradle of the Sun".

Anyone any clues? It would not have been published any later than 1972.

OMG, I found it!

After Googling AGAIN, I now find that it is Brian Stableford's "Cradle Of The Sun" (wow, my memory was right all along). Last time I searched there was nothing, but that may have been some time ago now. And it is a talking rat, not a mouse, apparently.

Part of the problem you had with identifying it may have been that at least one edition of it is one half of an Ace double (with The Wizards of Senchuria, so it tends to be cataloged in odd ways. (The other half is one of Kenneth Bulmer's Keys to the Dimensions series, which is why I know about it. If you get that edition, the Bulmer is very good.)

Thanks!