I have one as well stamped Erfurt 1916, serial number 8XX. See http://www.nramuseum.org/the-museum/the-...on-carbine.aspx for an example of what mine looked like before my Grandfather sporterized it. It uses a standard 98 bolt. Also, see http://www.youtube.com/watch?v=nT8Wih_XB-4 for an interesting video of one stamped just like mine. He even provides a drawing of the receiver stamp. You'll notice on both examples the rifle does NOT have the characteristic bulge at the front of the receiver like the normal 98s do.
Keith