Found recently another handmade 6X17 in Ebay. Appears that the film holder was made from two fused 6X9 film holders. The seller was generous enough to allow me to use the pics which is much appreciated.
The name of the camera is "Wide-tac". So far I didn't come across any source of information on this camera. Let me know if you know anything about this camera. Either directly email me the info, or use the comments section under the post.