;-) pleasure.
Yeah, the S10 filter is really well made, when you open it up, you'll find the plastic has metal wire reinforcing it in the actual plastic which appears to be sealed by bionic ultra wave technology :-) or something like that. There is no way in it, no seal or weak area. I use a BANDSAW and cut the end off in one go, smooth and quickly. Under the black end there's a plastic mesh then paper filter which looks a bit like a cars filter (old vw beetle). This is attached inside around the edges with a rubber solution which you have to get a Stanley knife in and around the inside all the way around to free it. Then there's a metal plate with holes in and a thin plastic gauze under this. This bit contains all of the charcoal, fine bits, not like on your BBQ. After you dispose of this there's another's metal plate under it with holes in, another thin plastic gauze then you're through to the other side with the screw bit on that attached to your mask.
It needs a REALLY good wash out, then I glue one if the thin plastic meshes over the screw part on the inside, glue one over the inlet part on the other side, again on the inside then apply some glue to the end that I cut off with the Bandsaw and attach it back on. Wrap a bit of black or red electrical tape around the join just for effects or slightly sand it smooth over the join to blend in if you don't want to use tape and there you go.
Yeah, should be able to do that with the paper template, just put a ruler on it or draw one on it so I know the exact size.
Hope that helps :-)