Recently got a donor car for my classic and i was told it had a remapped ecu but when i looked it doesn't have any brand names on or look anything special 

 

is there a way to tell if its standard or after market?

Might have a esl inside p

If it's a standard ecu ,remove it and pop the outer casing off and if it has been remapped it will have to have a esl daughter board fitted which will look like this one

Bear in mind that If the donor scoobs not the same phase as yours the ecu won't be compatible due to the differences in ecu plugs