Train Room Layout.......Only way to go is up from here....

Dan, It looks like you have come up with a good idea to add another level for the prewar trains.  That is really nice you are making it as a tribute to your dad.  I think what you use as a guard rail depends on how far the trains will be from the edge.  If they are close, then plexiglas may be the answer.  It looks like you just have the fascia on the main level attached so its top is a little higher than track level.  maybe that is all you need, but depending on the height of the upper level, it may block some viewing.  How high is the upper level?

Thanks next picture will show  that the track is 2 inches away  the edge....thinking of  foam  maybe 3x3 shave it like a hill  I like to get some green  paint  and add some lichen  to it  and staple it to the edge..so if if the prewar 256 flys off it would be  safe from falling... my two grand boys are 3.5 and 6 mouths!  never know when your watching  trains  and kids! lol

Here's the progress along the way ... I have to add my two prewar bell and prewar gateman . and a 191 repro villa with house , and some signals

i got for this project. Around the curves Im thinking maybe some coco mats 1inch painted green to match the prewar 191 villa look  maybe ,dont ever want any thing flying off....lol

Looking great!!