Will look very similar to a new one - electonic components rarely change their apperance with age unless subject to excessive heat - a poorly rated resistor for instance will blacken with the heat unless of sufficient Wattage. Photosensors, however, are unlikey to suffer this syndrome.
Use google - enter "photosensor" and click on Images to see lots of different (mostly new) photosensor pictures.
Peccavi, August 2009
