Hi Mr. Metronome,
Indeed there is a consistent inconsistency with the movement engravings - and it's not new as well. It's the very same with many vintage movements form PP (and, BTW, it's quite normal with other manufactureres as well).
I guess the only "logical" attempt is that there might be different batches in production, but for what reason the engravings are changed - sorry no explanation.
As for a possible "next Patek" - first, I don't own a 5107 (although I'd like to ) not sure which pictures you were talking about?
Secondly, it would help to know what are your preferences re. automatic winding or manual, is a date essential for you? Simple time only or something more complicated?
As 5196P was already mentioned (as you "don't like white gold, not sure you dislike Platinum either?) - personally I love the gold versions of 5196 more - strangely it's the dial which I prefer the "normal" version instead of the Breguet numerals platinum version. ;-)
So, any further hint for your preferences would ceratinly help
Best regards
Suitbert
ps.: Apologies for my tardy answers