149 unique levels (since you said there's 1 repeat) is still damned impressive! Though I haven't played every pack ever, I haven't seen any pack before with significantly more than 100 unique levels. Orig, Genesis and LPI all have well over 100 levels total, but a lot of those are repeats. Depending on your exact definition of "unique", LPII has anywhere from 98 to 105 unique levels*; which isn't significantly over 100.
* Depending on how exactly you count the 5 "Floater Frenzy" levels (unique maps but the exact same concept), the three "-tuned Lemming" levels, and "The Upwards Mission" / "The Downwards Mission".