It's called a fairing stick. Very simple to make. Just a thin strip of hardwood, a small piece for the toggle and some string. Tie the string to one end of the stick, thread through 2 holes in toggle, thread through opposite end of stick and tie back to toggle. You can make these any size you need to get whatever size curve you need. Here's a pic of the threaded toggle. Let me know if this doesn't make sense.
One side
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The other side
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