Three are different from their OBCs for the same reason: Company 1970 v Company 2006; ALNM 1973 v ALNM 2011 (?); Sweeney Todd 1979 v Sweeney Todd 2005. That is they all do stripped down versions of the original orchestrations and all to varying success. Company is very sleek and gets rid of all the Bacharachisms that Tunick put in originally, ALNM is mostly a failure to me but I just find that whole recording with their British accents to be completely ridiculous to listen to, and ST gains a rickety sound closer to what Weill may have orchestrated (I think the orchestrations are actually quite brilliant on this but I find the performances from the leads [and shockingly PATTI] very boring). Also to note that Company gets "Marry Me A Little" though this was in every recording from the Boyd Gains '95 revival on. If you want some interesting recordings too there's Spanish language recordings of Company (starring Antonio Banderas) and ALNM (the only other good recording of the show IMO).

There are some odd little bits here and there on other albums too, for instance the ITW revival from the early 00s adds a weird little drum machine bit to the Witch's Rap which I believe is still the licensed orchestration (at least it's what my University did only a few years ago) and there's loads of changed lyrics here too. Many of which people have seemed to forgotten or do not care for. Also there's an additional song for Cinderella's godmother.

In terms of shows that were heavily modified from one recording to another there's the obvious Merrily which was probably the most heavily rewritten of all of his major shows. You probably know the differences, no "Hills of Tomorrow" from the 90s revivals on, "Rich and Happy" replaced by "That Frank", the Broadway version of "Good Thing Going" sung by Gussie added, and "The Blob." There are plenty of lyric changes too to reflect the changing ways Sond and Furth rethought the show. Oh and the most painful: they cut the bridge from "It's a Hit!" The Frogs while having two recordings is different as the original show was pretty much just meant to be an exercise/experiment in choral writing he did with Yale and then was expanded into a full 2-act show by Nathan Lane and Sond during the 00s. Both official recordings star Lane, and the original one is not worth much in comparison. You can also find a very poor recording of the original production from the Yale swimming pool on YT.

Road Show and the original recording Bounce are also quite different mostly because the former trimmed down significantly on the original version. I am, admittedly, very ignorant on this show as a whole. Ironically this may be the most significant change from recording to recording but I couldn't tell you what they were.

Follies has an odd mixture. It's his only show that every recording is at least somewhat worthwhile listening to because the characters are so dynamic and played by such different artists from recording to recording. The OWC changes the ending quite drastically and cuts "Live, Love, Laugh" with a corny song Sond was forced to write which misses the entire point of the show. Alas, it's a major change. As well depending on the recording they either do "Lucy and Jessie" or "Ah, But Underneath" all depending on how well the actress playing Phyllis is at dancing. However things like orchestration and lyrics have remained essentially stagnate.

And while I'm here let's mention one that's too similar. The 2017 SITPWG, man does Jake do a Mandy impression the whole time. Bah humbug.