I would use a local rigger and have him get the parts. Anyone with a swage machine can make these. Provide the rigger the Rigrite link so parts may be purchased. That way the shrouds will be measured and built exactly to the length you have. The turnbuckles don't need to be Navtec since they are out of business. That way if a slightly longer or shorter turnbuckle is used, the rigger can compensate the wire length.