Yes, I do own the original photos and negatives. The 3x5 photo was scanned at 300dpi, but the photograph itself was the very heavyweight textured surface. A good clean scan wasn't possible, so I despeckled the textured noise out of the photo. I'm sure I also have the negatives to all the photos, but there are about 2000 slides and the same amount of negatives to go through, so getting you a good copy will take some time... PM me your e-mail and I'll get it out to you as soon as I can find the negatives.
ps: All the credit goes to Alex Tremulis for having the foresight to capture some amazing images...