Ok, 1.0.4 just went up with the last batch of bugfixes (hopefully), so let's get this started. In general, be careful you're only replacing dialog and other text and not programming logic, as that may have changed in various ways as well.
Here's my best recollection of where all the new content is:
Common Events:
The following new common events have text that needs to be translated: 242, 244 (the dialog should all be the same here as 115, just truncated so it starts at "There was no response as...". Just be sure you don't mess with non-dialog stuff.), 245 (again, largely the same text as 196 and SOME from event 92 on map 56, though it might be easier to just translate through again rather than trying to piece together, your call), 261, 266, 268, 269, and 270.
Map Events:
On 40, "GutterHub":
-126, 127, 128, 129, 130, and 131 are all identical, you can just translate one and copy-paste the others.
-125
-104 has a 4th and 5th page now with dialog. You'll have to copy-paste the whole blocking row there (this is the first blocking row leaving the plaza north).
-There's a new blocking row in the alley leading to/from Mahir's, starting with 135. All identical, copy-paste.
On 41, "MahirHQ":
-Careful when working with event 4, "Mahir". Should be 99% the same, but there might be a line or two that's different.
On 42, "PornStore":
-5 has new dialog
On 44, "StripClub":
-4, 5, 6, 8, 9, 20, 29, 30, 31, 32, 33, 44, 48, 49, 51, 52 all have new dialog. Note Mezz's comment to one customer thatgoesonandonlikethiswithoutspaces is SUPPOSED to fail to word-wrap and overflow the text box. That one's intentional.
-The blocking row at the door, starting with 7 have new dialog. All the same, copy-paste.
On 46, "stripclubrestrooms":
-1, 10, 49, 48, 54, and 53 all have dialog.
On 65, "Entertainment District 1 (SlutMode Ver):
-The blocking row into the alleys, ev 397 and 406 have new dialog. Identical to each other, copy-paste.
-There's a new blocking row of two events a little farther into the alley, 423 and 425. Identical, copy-paste.
Items: 38-41 are new.
That SHOULD be all of the new text for the THIRD content pack. If I remember right, you had already managed to translate up to completing the second pack, right?
I also collected a few notes when I started my playthrough of your translation, before stopping when I realized the version problem. I'll share those below so you can get to them on this pass/draft:
-Mouse vendor (124) in Haven not translated
-Bartender in hotel (27) had his name tag info deleted, so his name is displayed with the rest of the text. Text to search: "＜バーテンダー＞すみません、今はお飲み..."
-text for finding hamburger under empty bus stop (163,164) not translated. "Wait, there's something hidden under the bench."
-shopping mouse (118) and vendors (111, 110) in Haven not translated
-The color tag on one of the lines for the first porn shop scene is broken. Text to search: "c[2]もちろん本物のメズさ！だけどエッチが大好きな方のね". Check his other lines for the correct formatting.
-Missed the Hyena thug lines when first greeting Mezz in the alleys. Text to search: "Lose yer way bunny? Entertainment's back where you came from"
-A line from the first capture scene in the alleys by the hyenas in slut mode doesn't wordwrap/overflows the dialog box. Text to search: "メズは頷くと、彼のすべすべした皮袋を従順に舐めようと体を前へと押し出した"
Thanks for all the work you've put into this, and let me know if you have any questions.