I am trying to reattach a bootcamp partition located on a separate SSD to a new installation of High Sierra after FileVault trashed my existing installation. The Bootcamp drive is not visible in the Mac and the Mac drive is not visible in Windows.

I am trying to reattach a Bootcamp partition located on a separate SSD (in the Optical bay of my MacBook) to a new installation of High Sierra after the FileVault encryption trashed my existing MacOs Installation. At the moment the Bootcamp drive is not visible in the Mac, Finder or "Disk Utility" and the Mac drive is not visible in Windows or the Windows "Bootcamp Control Panel", (although it is visible in the Disk Management Widget). Anyone know how can I set this back up again?