Ben,
Rosedale was at a different location originally. But, if I'm not mistaken, the first course on the club's present-day property was laid-out by Bendelow with subsequent revisions by Ross, et.al.
As for Royal Ottawa, I visited the course two summers ago and found it to have tremendous potential to capitalize on its classic early 1900s architecture (Benedelow). But, you're right, as it exists presently, the course is messy, comprised of a hodge-podge of design styles.
There are some big square fillpads at Royal Ottawa that are really neat, but the putting surfaces that occupy those fillpads are tiny and circular. Many of the greens have shrunken significantly over the years, and have lost there original geometric shape. Others have been rebuilt in a modern-style and contrast the originals. The course also features remnants of some really cool cross-bunkers, and a few neat old "trench" bunkers behind greens.
All in all, there are some really interesting old-style holes at Royal Ottawa. With its classic clubhouse overlooking the 18th green, the course has tremendous potential to capitalize on its history by restoring some classic early 1900s golf architecture. And, as I understand, the club is very proud of its history.
Willie Park, Jr's Ottawa Hunt Club course was completely rebuilt by Tom McBroom a few years ago, and has lost its distinctiveness. Ottawa Hunt now resembles a typical 1990s era golf course. In contrast, what better way for Royal Ottawa to differentiate itself from other courses in the area, and other courses in Canada for that matter, than to restore that classic 1900s architecture that's out there, just hidden at present? Wouldn't that be neat!