I actually received a 180g record (Capital Records) that had around half of the circumference squared off while the other half was a normal lip. I returned it even though it played okay. I wonder if yours is a mistake too?
Is There a New Record Pressing Machine Out There?
I bought Wilco's newest Album "Cousin" yesterday and noticed something I have never seen before, the record has no lip. The label area remains raised but otherwise the record is dead flat. It is a very heavy record, probably 200 gm. I believe records had the lip to prevent the tonearm from floating off the edge with changers which were way more popular than manuals back in the 40s, 50s and early 60's. With manuals the flat record is easier to cue by hand.