Ref. http://www.ebay.co.uk/itm/391132899392 

I saw this singing bird in cage for sale close to where I live.
It reminded me that of all the singing birds offered on eBay,
99% are the small dome type and _all_ play exactly the same tune.

I always thought they were reproductions made from the 1970s onward.
Is this correct or did production start in the nineteenth century
and never actually end?  Most have the plastic gears and not brass.

Brian Chesters