Ran a Google on 2, 1 which gave me an alternative answer to 6,19 which still fits and does parse (although I'd never heard of it). However, once I've had to resort to Google, I tend to lose interest as any satisfaction from completing it has gone. Google also gave me 14,23 which, whilst it parses well, I'd also never heard of.
A bit of a disappointment (for me) from one of my favourite setters.