Does this help? It's all I got handy...
I finally found some plans/blueprints for a 1966 Ramirez 1a on the net and the pics of the interior top view of the Mark VI look very similar to the Ramirez blueprint plan. One interesting difference is that the Mark VI pic shows an extra brace on the top, in between where the neck meets the top and the long brace that runs near the neck-side of the sound hole.
It's a pretty big brace. In the Martin Guitar World, they colloquially call it the 'popsicle brace.' It's supposed to keep the top from cracking along the sides of the finger board and was introduced to the D-sized models in mid-1939. It serves a good purpose, but it also changes the sound. One of those trade-offs.
Here is a link to the Ramirez 1a blueprint:
https://www.amazon.com/Set-Classical-Guitar-Plans-Contreras/dp/B00PM2JAUW
Tom, I have a few questions for you. On my Ramirez 1a, the saddle was a straight drop on the sound-hole side and curved on the end block side. At one point, my luthier made a new saddle that was curved or rounded on both sides and the G string wouldn't stop buzzing! We went back to the original design and the buzzing stopped. It had something to do with the extra scale length. What is the saddle like on your guitar? Just wondering.
Finally, did you re-angle the Spanish heel neck? What is the string height at the 12th fret?
Thanks again. Great Work!
Harry/gilded