I don't know...I assume you can buy one somewhere, but you will still need a carabiner on one side to connect it unless the person making it has your saddle in hand. One of the advantages of a truly fixed bridge is no knots or carabiners.
Doing an Amsteel bury is so frickin simple. Don't underestimate yourself...you can do it.
And a locked brummel is not hard to undo. Get a few feet of 1/4" Amsteel and practice doing/undoing it a few times. And either buy a fid or make one (a piece of 2117 arrow works great for a fid) and it will be easier, but I've done it with just a piece of wire.
A stitch lock is even easier to make but they aren't as easy to undo, especially if the thread is the same color as the Amsteel. Use contrasting color thread for the stitch so it can be easily seen if you ever want to un-stitch it without destroying the Amsteel.
The easiest bury of them all is a whoopie sling. It takes literally a minute to make one and 2 seconds to un-make one, and its adjustable.
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