Has anyone has ever compiled a classification or set of pictures detailing the different types of pommels beyond the seen from the "celtic" era of swords besides the anthropomorphic types? I did a preliminary search of the site and while I found different blades I haven't seen much in the way of the other end of the swords from that era.

That is because unfortunately there is hardly any preserved, at least if you are refering to the La Tene swords. There are some irish examples a few british ones, but that's about it. Of Hallstatt swords lots of hilts have been preserved, but they are completely different swords.