From what I understand, the Ratzeburg Korths are all products of extensive hand-fitting and meticulous attention to detail by individual master gunsmiths. The newer Lollar guns utilize a lot more CNC automation to achieve similar levels of final fit/finish but with less actual man-hours of attention per gun. The upshot to this is that the older guns might very well be slightly tighter than the new Korths, but the new Korths are probably a lot easier to repair or replace broken parts with drop-in factory components, where an old Korth would pretty much need a very skilled gunsmith to do any work on.
Yes, you have it largely correct.
Even though the vast majority of Ratzeburg Korths were produced as standard models, they were essentially built like custom guns by master gunsmiths and machinists. (And Korth would build a full-custom, one-off revolver to your specs as well, if requested; plenty of Korths with engraving, gold inlay, and other bespoke adornments made their way to petro princes in the Middle East.) No automated equipment was used. Parts were precision-ground from forgings of undisclosed alloy composition with tensile strengths in the range of many true tool steels and maraging steels, and then deep-hardened, which is part of why they're described as revolvers designed and built without consideration for cost, as
@CraigC noted. (And which, in turn, is why the original Korth company suffered multiple bankruptcies and was never profitable.) The guns were hand-polished with sanding blocks, never with polishing wheels, and they show incredible surface evenness and smoothness, even with the major parts having been surface-hardened to 60 HRC. The end result is something otherworldly. The guns look like they were produced with extraterrestrial technology. They're just unnervingly perfect.
I have only held and worked the action of a Korth National Standard (imported by Nighthawk as the Mongoose) to this point, but my impressions are very favorable -- technically, that is, not aesthetically, although the National Standard / Mongoose is at least far more subdued in appearance than the other mutant rail monsters in the Lollar lineup. That said, they are certainly not, in CraigC's terms, "no expense spared" revolvers in terms of either materials or production methods. As you noted, the new Korths were redesigned to maximize automation and drop-in assembly and minimize man-hours and hand-fitting. Materials are also far less exotic. In place of the much harder and tougher precision-ground steel forgings used for all parts of the Ratzeburg guns, the Lollar Korths are machined from bar stock of steel alloys typical in firearms production. The frames are made from AISI 4140 steel, and the cylinders are made from AISI 4340; the barrels have variously been advertised by Nighthawk as produced from either AISI 4340 or Type 416R (stainless). These alloys are, of course, more than adequate for producing a very fine and very durable revolver. After all, these are the alloys used in almost every other handgun you can buy, and Lollar sources the highest quality steel for these grades. The Ratzeburg guns are something unusual, though; only a very small number of other handguns (e.g., Swiss SIG P210, Mulhouse-built Manurhin MR73) have made similar use of much stronger steel alloys than the standard 4130 / 4140 / 4340 / 416 / 416R / 410 fare (4340 being comparatively rarer in use and considerably tougher than the rest of those).
No doubt you are correct that both the procurement and the performance of service on the new Korths is a simpler matter. On the other hand, as with a Swiss P210 or a Mulhouse MR73, it's rare for the near-adamantine parts in the Ratzeburg guns to give their owners any trouble.