NFTs on bitcoin were not possible until 2014 (the op_return function was introduced in 2014). Namecoin is the first altcoin that launched in April 2011. The first asset on the Namecoin chain was on the 21st of April, 2011 (about 20 days before the first Punycode). Given that now all 2011 Namecoin assets have already been scraped, it is extremely unlikely to find art NFTs before Punycodes (but we are open to art interpretations for other NFTs!).