There is no statutory or regulatory authority for VA to reduce a total disability rating based on individual unemployability, as authorized by 38 C.F.R. §§ 3.340(a), 3.341(a), 4.16(a), based solely on a veteran’s removal from a “work possible environment.”  Such reduction of a total disability rating based on individual unemployability would be inconsistent with the requirement of 38 C.F.R. § 3.343(c)(1) that, in order to reduce such a rating, actual employability be established by clear and convincing evidence.