When comparing printing from digital fonts to printing from metal fonts, I'm not quite sure what wouldn't be "derivative."

The papers are different, the inks are different, as is the method of applying the ink. The individual characters are different, too. Each character in metal is cast -- each "e", for example -- and has it's own blemishes -- or uniqueness, depending on how you view such things.

The positioning of the letters in metal can vary as well -- in three dimensions, though oddly enough, "width" is usually quite well controlled.

Having said that, getting the ink to form the same with metal/letterpress as with digital/offset is a challenge few are willing to undertake, or have the skill to achieve. I think Carter did rather well, his digital Monticello is a bit better than the Linotype 202 (photocomp) Monticello.

Is this what you had in mind? Or did you mean the Linotype (linecaster) Monticello differs from the ATF Oxford.

From another source:
http://luc.devroye.org/fonts-33550.html

Linotype Monticello was designed by Griffith in 1946. Its design is based on James Ronaldson's Roman No.1 and Oxford Typefaces from American Type Founders and was revised by Matthew Carter while he was working at Linotype between 1965-1981. Mac McGrew: Monticello is a Linotype recreation of America's first great typeface, Binny&Ronaldson's Roman No.1, cut about 1796 by Archibald Binny in Philadelphia.

. . .

C. H. Griffith, Linotype typographic consultant, made a detailed study of Binny's type and redrew it in 1946 for the requirements of Linotype composition and modern printing conditions.

Even though the linecaster & its duplexed mats required differences from foundry type, to the extent possible, Griffith went ahead & allowed as many of the complications as possible -- the full-formed italic j, f, etc.

So I'd say it is an adaptation, not derivative.

& I believe Matthew further removed some of the linecaster compromises when he did the PostScript version of Monticello, though I'm working from memory, & might have that wrong...

BTW, & Updike notwithstanding, Binny & Ronaldson's fonts are usually considered a, what, "not-the-best-quality" ripoff of fonts from the U.K.

Rather than simply copying the original, Griffith took into consideration such factors as the heavy appearance of its lowercase ... [he] had to thicken the capitals slightly...

In this, Lawson is incorrect. He either misinterpreted or misunderstood his sources.

The case was in fact the opposite. Griffith chose to reduce the weight of the capitals slightly in order to get a more appropriate balance under contemporary press circumstances.

As Griffith explained in an article in Linotype News in 1951:

“Before the Monticello project assumed tangible form, Fred Anthoensen of Portland, Maine, provided specimen pages set in Oxford type and printed on a variety of papers commonly used in commercial and book printing. These specimen pages provided the means for an analytical study of the contemporary behavior of the type in comparison with its action in the medium for which is was originally designed. It’s finer qualities [ . . . ] failed to materialize to the last degree when impressed on modern papers. On relatively smooth stock the capitals were as weighty and obtrusive as Scotch, an effect quite contrary to Binny’s intent. This, and other inconsistencies, made it clearly evident that Binny’s type could not be satisfactorily uprooted and transplanted for contemporary printing by a weight-for-weight and curve-for-curve copy of the original.”

Referencing some of the same material I just quoted, as well as drawing from correspondence, Creesy describes the situation more explicitly in his 2006 article from Printing History (which was linked in that other thread referred to above):

“Griffith was particularly concerned about the relative weight of the capitals and lower-case letters. He had been comparing his favorite historical example of Pica No. 1, Marshall's Life of Washington, with samples of Oxford set for him by Fred Anthoensen, whose Anthoensen Press in Portland, Maine [ . . . ] His theory was that Binny had to thicken the capitals because otherwise, under the conditions of early 19th-century printing – using damp rag paper, ink balls, and heavy impression under soft packing – they would look too light relative to the denser lower-case letters. But when the very same type, represented by Oxford, was printed with a modern letterpress – using smoother papers, precision form rollers, hard packing, etc. – the capitals looked too dark. Consequently, he thought he would have to restrain the capitals "just a shade" to get the desired balance.”

I encourage you to read Creesy’s entire article.