Yes......actually most are. On the top, all the GP9s are custom.....I did these before Atlas released their high hood version, and noone has ever done a chop-nosed version. On the second row, the remote control caboose, the SW1200, the SD9, and the GP35 with dynamic brakes are all custom.....I didn't do the SD9. On the 3rd row the unpainted loco on the left will be the sole GP19-1 MRL did. The Operation Lifesaver SD40 is custom, and the unpainted loco is the sole MRL SDP40. The rest are all factory. I need to get back in the paint booth and finish. Sorry the pic isn't clearer.
That's a great source........but it would be nice if there was a source that could be searched by RR. I have a pretty good idea of what has been released, but no idea as far as road numbers go. I'm pretty sure I have at least one of everything, but certainly not EVERYTHING. And I have a lot of custom painted stuff, which sometimes clouds my memory as far as what was factory and what was custom........and to cloud things further I have some non-prototypical stuff that I did just because I thought it would be cool to do or because it was "close enough" before any manufacturer released it. There IS this source which lets you search under manufacturer, Railroad, ect. and it's pretty good, but they rely on getting info from you and me, so not sure if it's complete........but it's a great start. N Scale Model Trains Database Index (trovestar.com)
This is probably the best source of MRL items produced. https://www.trovestar.com/generic/index.php?Collection=4&Reporting Marks=MRL