Photography stock moving PC to mac

I'd seriously recommend you reformat those externals. GUID is my preference so cloning, if ever the case arises, is not an issue. Having a Mac interface with a NFTS partition will, at some point or another, be problematic. 3rd party software in this area is quite geeky.  My view is a DOS partition is just as bad though many do it.

Also think disk repair tools. If they run on a Mac, they will not support a Windows partition. I know none of the more popular ones support NTFS. Perhaps there's some little utility out there, supported, at least supported today, that can manage this, on your valuable files.