The change happened after System 7 (7.1?) came out because you can boot System 6 on an LC on a floppy and think nothing of it. But Boot System 7 from a floppy and you will be pulling your hairs out! I got 5 LC’s, 3 are Dual Floppy but 1 is actually has dual floppy drives, the other two have a hard drive and a plastic cover over the hole. The other two are like these – the hole is filled in like the LC II. They must have switched when they were making the LC II cases and decided that it would be easier to use the LC II Case for both machines than to make a separate LC cases with the slot cover and the LC II cases with the hole filled in.