Hey everyone, sorry for the late reply and thanks for all your input and detailed suggestions. I read them all with interest. Reading through your comments I started itching to spend, spend, spend, but in the end I accepted that the original recordings were higher in sentimental value than audio quality so I've gone for the cheap option, using equipment that I already had - a cheap cassette player via Balance.
At the risk of infuriating the drummer I've reduced a bit of tape hiss using the Low Pass Filter in the SSL mixer. Why would that infuriate the drummer? I'm sure, if I told him, he'd hear the cymbals had lost all their ring.