Stallzer,
The one on
ebay is interesting, but seems to be a color changeling, if memory serves that type of British receiving mark that you see on it wasn't used until quite a while after the stamp was no longer in use.
I personally wouldn't buy those other stamps, although the last one looked possibly OK, the only poorly centered or faulty 24c stamps I ever buy are multiples for plating purposes or straddle pane copies, captured imprints, etc. I have a few that are very off center but only if they are capable of being plated (Position 1-10L or R, or Position 90-100, or 1, 11, 21, etc L or 10, 20, 30 R, etc.
Yes, the 30c has obvious corner creasing at the upper right.
What's easily as curious is seeing images online of these stamps and then seeing them in person during lot viewing, oftentimes you would think you are looking at totally different items.