Thanks for the reply. I was able to do a bit more research and found an exploded diagram of the router but the copy they provided is horrible, not much detail to the pic and no part number for the sub base.
I did find out that the 315.17351 "looks' to be about the same design as my 315.17350, so I now have one more option for parts. The manual would give me the part number so I could also search for that. This is why I'd like to find out if Ryobi made a sister model, they'd share the same parts and I'd have yet another model to look for.
An old eBay page shows the 17351 and you can see two small threaded holes on the metal case just below the depth of cut adj ring and Craftsman name. I am curious as to what their purpose was? I don't think it had a light or plastic shield attachment.
It may be old and not of any real worth $$$ wise but repairing it and having yet another "toy" in my collection at so cheap a price makes fixing it worth pursuing. Satisfaction in getting it to function properly is its own reward!
I'll keep looking for a manual, someone, somewhere, must have one even if it's the Ryobi version.