Looks like you did a bit of custom mixing such as "stereo" panning on the piano channels. I didn't critique the mixing as a 1:1 as such, however it looks like you did want to retain the same echo so in that end you forgot to raise the echo volume to match SMW's master volume. In future ports, to do this look at the SPC Player MasterLv. Take SMW's MasterLv and multiply that by the original game's EchoLv and divide that by the original game's MasterLv. Since SMW's MasterLv is 7F and most games have it lower, you should always get a higher EchoLv than the game's original EchoLv. I would suggest using key off gain for those rests like the original though. Hope this helps!