Thanks Sea Rider! That's pretty much what I was wondering. This one does seem like a higher end model. It has the "sevtest" inflation gauge on the side, so I can tell the right pressure for the main chambers.
The transom did come with a couple of extra steel rods that brace the transom to the wood floor, but have since disappeared. I could probably fashion something, or have a machine shop cut and bend some new ones for me. Last time I just used a rope, but that only stabilizes in one direction. It does say on the side that it can accept up to a 7 horse, but I found a good deal on a 5hp Coleman which I've used a couple times. I'm thinking I should get those support brackets redone before I try again. ...and I think I've got a leak somewhere that is affecting stability.
It's a pretty neat lil boat, so I figure it's worth the time and effort to get her into tip-top shape. I appreciate the help!