The M420R and the real GP38-2W had 4-window Canadian safety cabs. This GP38-2W has a 3-window early US EMD safety cab. Weren't the first CP SD40-2Fs delivered in 1988?
Unfortunately, the JPEG artifacting in your photos is so severe that I can't make out what production phase the GP38-2 is. Does it have wire-mesh radiators or raised corrugated radiators? I think it has the corrugated style, which makes it a Phase 2 (basically, late 70s) GP38-2. A Dash 2 from, IIRC, late '82 on would be Phase 3, with an angular blower duct like on an SD50/60.
What I'm saying is, I like your model, but it can't pass for a possible new-build GP38-2W. A rebuild, yes.