I think there were a wall bracket, I have seen some used for sale here in Denmark, I do not know if they are original or some other maker than B&O.
With respect to the link solution, it is in no way possible. The MX1500 have neither datalink, nor masterlink. One possibility is to use the scart connection in some way (take the sound in via a scart to RCA cable), but I do not think this will work.
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Chr.