WHY ARE THE SAME BOSSONS sometimes DIFFERENT SIZES?     

Some Bossons of the same model appear to be different sizes.....  Why is this??

An Example of this is two Sikh that are in my collection. One of these Sikh is definitely larger than the other.

An explanation that has been suggested is that as the 'moulds' aged they tended to enlarge themselves with use.

This subsequently resulted in larger models being produced from the old moulds.