I found Peter's mention of CF Martin interesting, since (as I understand it) he introduced the violin-style mortised neck to guitar making. The integral neck block in the violin under discussion here continues to be used in Spanish guitars. Glenn Wood tried to convince me one time that that the integral block, also known as a "Spanish heel" is so named because the extended section looks like the heel on some archaic Spanish boot. I thought the term simply referred to the fact that it is used in the Spanish guitars. Maybe our Spanish friends can comment on that.
Regardless of all that, I think the integral block in this guitar is interesting for another reason that is relevant to the observation that it was used on good violins early on, and on cheap violins later (albeit with many exceptions). I have only seen the integral block with that platform extension on quality Saxon instruments (and on today's Spanish guitars), and I have only seen abbreviated integral blocks (ie, without the platform) on later, cheap violins. Not saying that that's a rule or any kind on identification tool -- just that that's what I've seen.
Sorry we're deviating, CF Martin learnt his trade with Johann Stauffer, and in fact one of the earliest Martin guitar, New York 1835, is virtually identical to his former employer's work in Vienna. (including Alpine wood for the front.)
Neither have integral neck/block, always two separate pieces. Block usually spruce ( I am reliably informed)