I've been sporting an Arca rail from Nelson Precision Manufacturing the past couple weeks. Took it for a spin at a match last weekend.
Good looking machine work, and great price. Comes with new hardware and mounts through the plastic or metal forend into the aluminum backbone. you can get them in 10" or 12" lengths and they fit the W3, Bravo, and X-ray chassis. Made with 6061 aluminum. I have the 12" version
(not a vendor, just a customer who loves a product and spreading the word!)
Good looking machine work, and great price. Comes with new hardware and mounts through the plastic or metal forend into the aluminum backbone. you can get them in 10" or 12" lengths and they fit the W3, Bravo, and X-ray chassis. Made with 6061 aluminum. I have the 12" version
(not a vendor, just a customer who loves a product and spreading the word!)