AE Bounty initial work

Just a few pics of some corridors I have been making for AE Bounty games in 15mm. This is one corridor, 20cm length,walls 30 mm height, useable width of corridor 45mm. I built out the shell with basswood, then cut up and glued pieces of plastic IMEX platformer,hexagon builder? terrain from my rather large bitzbox. I purposely left the corridor ends open, to either cap onto another corridor or room. Next step some rooms. I am planning small medium and large rooms, of I guess basic square and rectangular shapes.
You might not be able to see in the pics, but my mercenaries from Critical Mass Games have custom bases made from the same platformer plastic bits. My ultimate goal is to create one master of everything and cast a million copies( like I need another hobby).
I have done some casting years ago, and I suppose I will use the RTV mold, with legos as a support.I am leaning on using resin ,but I may try hydrocal light, although these walls may prove too thin for hydrocal.....any suggestions from the castiing community? I am planning on making 1 piece molds so the corridor/room will be complete when cast.