Here is a list of links to various websites of interest?
www.pickelhauben.net
https://www.weitze.net/
http://imperial-antiques.com/
http://bpnemec.com/pickel.htm
http://www.prussianglory.com/
http://www.kaisersbunker.com/
http://www.germanmilitaria.com/
http://www.hermann-historica.com/
http://www.worldwar1.com/sfgph.htm
http://www.erstes-garderegiment.de/
http://www.militaria-online.de/eng.html
http://ageofkingsmilitaria.com/index.html
http://www.kaiserzeit.com/index.htm#top
http://www.austro-hungarian-army.co.uk/
http://www.kammerbulle.de/Hauptseite.htm
http://www.saxoniamilitaria.com/Helmets.html
http://www.germaniainternational.com/khelmets.html
http://www.users.hunterlink.net.au/~maampo/militaer/milindex.html
http://home.12move.de/home/joerg-dehn/Pickelhauben/pickelhauben.html
www.pickelhauben.net
https://www.weitze.net/
http://imperial-antiques.com/
http://bpnemec.com/pickel.htm
http://www.prussianglory.com/
http://www.kaisersbunker.com/
http://www.germanmilitaria.com/
http://www.hermann-historica.com/
http://www.worldwar1.com/sfgph.htm
http://www.erstes-garderegiment.de/
http://www.militaria-online.de/eng.html
http://ageofkingsmilitaria.com/index.html
http://www.kaiserzeit.com/index.htm#top
http://www.austro-hungarian-army.co.uk/
http://www.kammerbulle.de/Hauptseite.htm
http://www.saxoniamilitaria.com/Helmets.html
http://www.germaniainternational.com/khelmets.html
http://www.users.hunterlink.net.au/~maampo/militaer/milindex.html
http://home.12move.de/home/joerg-dehn/Pickelhauben/pickelhauben.html