Yes, the MBSGB still exists and is alive and well.  The membership and
correspondence secretary is:

    Alan Wyatt
    The Willows
    102 High Street
    Landbeach, Cambridge CB4 4DT.

The phone number of the president:

    Arthur WJG Ord-Hume
    Phone: (01483 574460


They have a quarterly magazine which is just full of great info. You
need to get a copy of Bowers, Encyclopedia of Automated Music Instruments
from Nancy Fratti at musicbox@sover.net, so you can better enjoy your
treasure!

If you want to share info about your treasure on the MMD, maybe I can
help you figure it out.

Regards
Larry Greenfield

musicbox@ix.netcom.com