Long or short Pbox hinge?

[flehto]

Always wondered about the purpose of  long  Pbox hinges that have "outside"  knuckles on the finial....when just having knuckles on the finial that are as wide as the lid will  do the job …...Fred

[D. Taylor Sapergia]

It might be just as simple a thing as style Fred.  Perhaps some builder thought that ending the hinge at the side plates interrupted the look, so built them all the way across.  They serve no appreciable function, as far as I'm concerned.