"Not precisely what you are asking for, but I think Wittgenstein's Big Typescript is an important work for appreciating and navigating the distance between the Tractatus and Philosophical Investigations. It bears some important resemblances to Philosophical Remarks.

Philosophical Remarks was essentially a report written in 1930 when it came time to approve Wittenstein's research grant. As such, it is somewhat unusual in that Wittgenstein actually completed it with the intention that it would be read by someone else.

Big Typescript is also known as MS 213. It was written in 1933 and represents Wittgenstein's attempt to produce a more traditionally structured book (with chapters and chapter titles). It contains many passages and ideas that make up the posthumously published compilations of Wittgenstein's notes, as well as early versions of passages that later appeared in Philosophical Investigations in an extensively revised and rearranged form. These early versions often provide greater insight because they are generally longer and appear in a more natural context than they do inPhilosophical Investigations. Furthermore, in MS 213, Wittgenstein provides some of his most extensive explanations of what he was trying to accomplish in the Tractatus, usually phrased in the negative — i.e., he writes about how he changed his mind about the ideas he attempted to express in the Tractatus, where he no longer agreed, etc. Now he did not necessarily refrain from changing his mind again by the time he wrote Philosophical Investigations, but at least the transition is made much clearer as a result of reading Big Typescript.

After reading Wittgenstein for many years and a handful of secondary texts, I can't emphasize enough how illuminating Big Typescript is. I really don't have any idea how anyone can make any significant progress in understanding Wittgenstein and Philosophical Investigations without it. I also now find it difficult to read any of the secondary literature that does not refer to it in some way, for the same reason. It is simply too easy to misunderstand what he is trying to accomplish in any given fragment of his later writings.

I personally found Investigating Wittgenstein by the Hintikkas and Wittgenstein on Mind and Language by Stern to be very helpful in elucidating this "transitional" period. Non-coincidentally, IIRC, both books were written in reference to MS 213, before it was translated and published as Big Typescript. It's also probably worth reading Wittgenstein'sRemarks On Colour, in part because it is again one of his few "nearly complete" manuscripts. I would also recommend obtaining German-English texts for these works as much as possible. Wittgenstein wrote notes in German, except where he used English in order to make some point about translation between two languages, different sets of homonyms, or some related issue. There is tremendous inconsistency in how certain key words he used repeatedly are translated into English, and almost all of the instances in which he compares English and German idioms are systematically reversed in the English translation.

Finally, you may be interested in A Companion to Wittgenstein's Philosophical Investigations by Garth Hallett. It is essentially a concordance to Philosophical Investigations — the author is in fact a Jesuit priest — and it describes in depth every possible connection of any given passage to every other similar or related passage in Wittgenstein's other published notes and probable or possible sources based on what he was known to have read. I have not used this book extensively, and it is impossible to read on its own. But perhaps you will find it interesting to have as a reference." Sugestões por cobaltage.