The 917 was known as the Sportster. It was the shadow pattern version of the 920 Sportsman's knife with a fancy milled back. The blade configuration was the same on both knives. Go here, you'll find it if you scroll down to page 13. The Sportsman's knife is also in that catalog on page 4.
http://www.collectors-of-schrades-r.us/ ... W-CATS.pdf
It was only made for about two years, 1953 and 1954. Sort of morphed into the 906 in 1957 but in actuality that was a completely different knife.
Show a picture of yours if you have one. I seem to recall seeing that one in waterfall celluloid as well (even though I've only seen it offered in "Red Fiber") but I might be thinking of a different knife.
Here's a picture of one that was posted on BF about ten years ago:
Eric