Hi Doug,
I had the same concern...ruining the woody look.
I used stainless piano hinges, and covered them like they did it in the old days.
Back then, a piece of treated canvas wrapped around the outside of the hinge, and was secured behind the hinge on both sides by the hinge screws.
Being that canvas wasn't a great outdoor material, they didn't last long, but they did work well while it lasted.
I chose a vinyl material, such as is used for automobile vinyl tops.
I used a buckskin color to help blend in with the wood.
Since the trailer is stored inside, I expect to get 10 years or so out of it before age takes its toll.
In ten years, it will be time for close inspection of several areas anyway to maintan or renew seals.
Rob
Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...