Alvin,
Sorry to be so late posting this, but I missed your request for a photo.
This is a photo of the back of the bolt on the 1920s commercial luger that I had posted questions on earlier in this forum. The number on the bolt appears to be either 55 or 56.
If you need more, please let me know. barr
http://forum.lugerforum.com/lfupload/20s_com._bolt.jpg