Thanks guys! I was hoping you two would chime be clearer...I was inspecting from the top after having removed the cap and the dichroic reflector. The melted plastic filter in question is under the top clear glass piece and the four adjustable filters. I was peering down inspecting the action of the filters by zeroing them out and it was only after I had retracted all four filters that I noticed something that looks like a melted plastic filter underneath it all. I've yet to power it up and open the shutter so I haven't had a chance to inspect this from below. Am I wrong in thinking that you can approach the filter assembly from the side? It looks as though the cover of the head comes in two after you remove the screws.

When I borrow into this deeper I'll take post some digital shots. Thanks again for the info!