Trying to create a shader for a filmstrip - 35mm/70mm projection style

[GregCooper]

I'm trying to create a shader for the above that works under different lighting conditions. My approach so far is to use a Vray 2sided material with a VrayMtl plugged into one side, the mesh has no thickness. The VrayMtl has a texture plugged into the diffuse channel and the same texture (inverted and through a colour correct node) plugged into the opacity channel. This is giving me a result I'm pretty happy with in bright lighting but over a dark background this breaks down in the hotspots of the texture. I get a weird battle between the white in the diffuse channel and the opacity when its at or near 100%. This makes sense from a technical viewpoint but I'm not sure how else to do it. Am I approaching this wrong somehow? I've tried experimenting with refraction but that looks kinda weird. I could give the mesh thickness but would prefer to keep this without thickness if possible as it's already part of a rig. See attached screenshots.