Hello,
Cool idea, I had similar thoughts some time ago when I was making maps of Janissary recruitment in Ottoman Algiers. I'm an urban planner by trade and have adequate skill in GIS mapping so I'd be happy to contribute that to this project if it gets traction.
The easiest thing in terms of presentation would be to build a GIS database along the lines outlined by Ed, map the various features and export to separate Google Earth kmz files. These would be posted on the Forum and users would just download and open in Google Earth. This would save us the need to build an interface webpage.
This would essentially be an "EAAF Atlas of the Construction, Decoration and Use of Arms and Armor: in All Places and Times"
Emanuel