I have some art that's been sold as ebook covers and in currently displayed in semi-private online galleries. However, they are low res and only I can produced the high res 300dpi versions.
How would these be considered?

Sorry for the delayed response--it took us a while to think this through fully.

Pieces in a semi-private online gallery would be acceptable, with the understanding that they'd be considered reprints; the ebook covers less so, as we can't even pretend to have exclusivity on them for the 6 month period we're asking.

I have a couple of pieces that I'd consider worth submitting, but they're currently up on deviant art.

Would they be considered, if I were willing to take them down for the period?

Yes, that would be fine. We'd love to see them. We have a clause in the contract asking for exclusivity for the run of the issue you're in--which would be about 6 months, plus the precursor time. If you're okay with that, sub away!

And a note, on that--they would be considered reprints, from being released in non-private online galleries in a resolution comparable to that of which we'll be selling in the pdf (web resolution, 5"x8", ish).

Okay, actually, after lengthy deliberation--we're scratching the whole "reprint" idea of art, here. Anything goes for our full rate, though we're still looking for 6 months exclusivity.

We hope to find artists who want exposure to a broader audience for their work, exposure to a world-wide market. While we don't have the pockets to commission art-to-match or illustration, we can offer the artist a little extra cash for work they have already done, as well as a great cred for thier CV.