I say "and/or" because I barely know what I'm talking about. What I do know is I can't use Original Year in Strawberry because that value for FLAC files seems to simply mirror whatever Year is set to.
For Apple AAC files (ID3v2), on the other hand, Strawberry's Original Year works great. But not so much for FLAC's vorbis metadata.
I realize the standards for using ORIGINALDATE, ORIGINAL_YEAR, and/or ORIGYEAR are a little loosey-goosey, so I'm not sure what all the ramifications might be to implement this.