OK guys, sorry, I've been asking a lot of "Should I replace this part?" kind of questions lately, but here's another one.  I removed the charcoal evap can a few days ago and now I'm wondering what I should do with it.  I definitely need to replace the filter that's in the bottom, but I'm not sure where I can even get one.  I'm thinking I'll need to make one, but not sure what material to use.  Second, is it possible to replace the charcoal inside?  I've heard that a suitable replacement is fish tank filter charcoal, but I'm wondering if it's possible to get to the stuff without destroying the  thing.  Third, I think there's a check valve at the top of the can, is that replaceable?  Finally, what about replacement options (as a last resort)?  The parts houses don't seem to carry them and the ones on Flea bay are originals (no better than mine, maybe worse) so it would be from a catalog -- about $80 or $100.  Seems like I could spend my money on a lot more "value added" parts.....  I would like to keep the system intact, though.  This system actually does some good environmentally and it doesn't seem like it has a major negative impact on perf. I've already eliminated the cat and EGR so I guess I should keep something emissions related on this rig.  (My '76 L-48 came from the factory without a smog pump or EFE)