Per the specs, that adapter should fit an empeg without a problem. It states speciifically that it provides for DIN mounting. You'd better have another (close) look. It might be tight, but the sled should fit the top hole. Unless of course you didn't get the correct part. You might not want (or be able) to use those side parts with the holes in them. Those might be for non-DIN applications. You'd then want to support the sled from below with a little block of wood or something.

Bruno