For Migration period stuff you should be able to run down the Merovingian arms fairly easily, there has been a lot published on them and the museums of France and Germany should have findable items on line. I suspect you will have better luck finding artifacts by searching for site or tribe names, rather than generic period names, try Vendel or Valsgard f.e., or “illerup” for that bog site in Denmark that goes from Roman to 5th century IIRC. I’m attaching a figure of sword hilts from “Waffen und Gräber. Typologische und chronologische Studien zu Skandinavischen Waffengräbern 520/30 bis 900 n.Chr.” by Jorgenson (as with the later Viking period, there is considerable overlap in the Continental and Scandinavian material, especially in swords), most of the written material on your topic is not in English I’m sure!
The Cleveland Museum of Art has some Frankish stuff, here are a couple saxes:
http://www.clemusart.com/explore/magnify.asp?woID=9011
I’ve been studying Migration period spears, they seem mostly leaf shaped & socketed, and there are subtle and not-so-subtle variations in blade and socket proportions over time & amongst the various tribes; some areas got more angular and at least one tribe in the Baltic area picked up the tanged spear idea from somewhere, arrows commonly had tangs in N. Europe, spears had sockets (here is a ritually killed spear from them).