How to decipher the MS?

[oshfdk]

Just to give me some idea of what this might look like, I passed a piece of the previous post through a script that mimics a scribe that would confuse with 50% probability the following pairs of letters: a/e, m/n, p/b, t/s, l/r and also will remove 25% of spaces.

emd now suppotethes you ele an eurobaen malchent whohet rivad in myemmal or thangheifolefaw yaels andyou heveraarnad tha locarremguagewerr enough so ordal food emd heggla epoutshaaxchamga lesa of nuskets vslupiet, put notnuch beyomd shat. amd, pefola going pack hona, you remenpeltha blonite younede toyoul bhysiciam umcla so blimg hinsona nadicel emdharpel bookt from sha bleca. just cobying them would ba poinsrast tince neithal you nor your uncle cem laad thenasive tcribs. fol sha tana leatom you cemnot tlamsresa shebookt imso rasimor youlvelnecurel.  thussha bets youcamdo it devite e phometic tcribs fol tha rocal remguegaand bay a rocel toreadshe bookteloudwhila you seka dictation.  youomry undalttamd tomeof the sext, end mavel haeldarl thotenadical talmsemd plans nenas; butyou hopa thas, pack homa, you cem uta whet you kmow of the renguaga sofigure out the rats.

It's possible to match it knowing the plaintext, but I'd say it's extremely hard to read it. Decoding even a simple substitution (that is, a custom phonetic script) on top of this doesn't look very straightforward.

Edit: I know that confusing letters and confusing sounds would produce a somewhat different effect, but I still think the above is a useful approximation.