Great collection of photos! Nice work!
My best explanation as to why there would be discrepancies in the two tracker sites has to do with the following:
1. I understand they scrape data from other sites and may not do it consistently, there could be bugs.
2. Although it's simple and straightforward to monitor an address for 1BTC to appear ("funded") and then to disappear ("spent"), there is likely to be differences between the way the two sites interpret balances on self-funded bars, the "roll-your-own" addresses I sold in the past, and the relatively frequent cases where people add extra funds to their coins, reload them after redeeming, or otherwise keep a non-zero balance on the addresses after opening them.
Is there a more canonical dataset (that is easily human readable) than the two tracker sites? This listing is concerned with the coins that were minted, not with how many remain.
Did you mention having plans to make all the PDFs/images of your scanned coins publicly downloadable? I wanted to try get some images from your site too if you have.
