Any use ? The problem will be that any third party inspection is going to look for approved equipment not home made
The curious thing about this topic is I could not find any information that would suggest what that approval might consist of. Suppose the installation used a Medical Grade power supply (or any power supply for that matter) which was UL, CE, etc approved; would that be considered "approved equipment".
The little research I did on this topic (NEC 2012 and UL 676) concentrated on bonding of metal parts and use of GFI / RCD devices.
Also the OP mentioned the original lighting (hopefully "approved") did not even have a split bobbin transformer.