Re: retracting transom straps on trailer
Our Shoreland'r trailer came with them. Name says "Boat Buckle". Website, of course, is boatbuckle.com. I looked at the website and I think the model that's on our rig is the Boatbuckle G2. They also make one called the Boatbuckle G2 Stainless for saltwater.
Anyway, they're pretty cool and very easy to use. The website says you can get them at places like Gander Mountain, Overtons, West Marine, Cabelas, and others. They come with a 1-year warranty.
Hope this helps.