Will a shield built fo mega snap on mega 2560

Sure.

It doens't connect to the ISCP connector, because it doesn't have the mating connector.
But the other ones all seem to be there.
It also has a field of 2 * 6 solder pads, like the ICSP.
I can't tell for sure but it is possible that this leads to the same pins as the ICSP connector.
But if you have no need for that connector, it'll be fine.