The website that has the serial number information for Collard & Collards is:
http://www.ukpianos.com/info/pianos/collard.php3
However I am confused about this, as another web site states that the company was known as Clementi from 1822 to 1832. But the plate has the inscription C&C on it and it has the rounded sharps that are known to be a collard and collard thing. The web address that I got the info is :
www.ptg.org/museum/ english.htm
Thanks for any and all advice!!!