Hello!  I don't know what "large" exactly means for a music box movement,
but if a 48-key (plus 6 bells) movement with 23.5 cm disc is big
enough, I can help !

We make new versions of the 23.5 cm Kalliope disc music box, and we
also sell the movement only; the price is DM 1450 (US$ 840).

Of course, our movement is much smaller then the Porter's movement,
but there is also a little difference in the price.

Greetings from the romantic part of the Rhine.

Joerg Wendel
mmm-gmbh@t-online.de