There are a number of way to identify and age a Pelham Puppet, and being at this site is the best place to start
First you need to narrow down what type of puppet you have, then the character, and then its age
Have a look through the catalogues and leaflets under the "Information" tab. These can show you many of the puppets made, their types and names. Most puppets are common and so listed.
Once you have found the type of puppet ( be it SL, SS, SM, Display or another type), go to the "Types of Puppets" tab and select that types individual section. This area is always a work in progress and grows day by day.
If you find your puppet, then one way you can age it is by viewing the boxes section under the "Identification" tab
I think you are getting the idea but if all else fails, simply post a picture n the Facebook page