I gave it the 5 minute whirl, it's late here.
The most noticeable change you can make is to create a new CBM using Photoshop, the elevation file and the type file, see any recent SEA terrain. Dux and mrmidi are experts at it, but with your skinning experience you should be able to figure it out.
I think you need to walk the track waypoints, looking for waypoints that double back. The train for the north ammo factory was acting wonky on my FE. btw, it's best if the road convoys are only ~8 miles long making the trucks run at 45mph instead of 60mph, but it's your call.
Are you sure you want the ammo factories in the center. They look pretty vulnerable and I don't think you want a side with no ordanance for hours at a time. You could exchange the refineries for the ammo factories since they're normally useless anyway, but htc might object to the game play impact of any factories out in the middle like this.
You might also want to give some thought to shore batteries.
I love the snow, but I don't think htc will accept it in an MA terrain, be great if they did.
I'm not sure about 33 bases per side for the MA but the spacing looks good, I think it'll play well in the MA. Nice job.