(answering my own query) ...

Tivoli Support has, quite promptly, answered:

    The TSM 4.1.2 client is compatible with ADSM 3.1.  Some
    functionality offered by TSM isn't available, but the client will
    work.  IBM/Tivoli recommend you upgrade to TSM before using in a
    production environment,  but  I understand that isn't possible
    when using VM.

Thanks to all that answered on and off the list, wayne

Wayne T. Smith                          ADSM AT Maine DOT edu
ADSM Technical Coordinator - UNET       University of Maine System