The 152 haven't read the POH, and will therefore happily fly above MTOW.
Yes. Folklore has it that the POH was written for a short grass strip belonging to a mid-western farmer at 8,000' and 30 degress C, so on 2km long tarmac runways at sea level in Scotland's normal summer temperatures you get a different answer.
is this last comment true that it can be flown above the POH MTOW?!
If by "can be flown" you mean "will it fly" the answer is "yes". It's not legal, of course, and the insurance won't be valid.