Just use the disposables that way you know you have fresh and working hopcalite in there.
X542442 Lawrence Factor Air Filter
With a gas engine its not worth the risk to pack your own on a final filter needing/deserving hopcalite.
Putting it back in the box after use or maybe storing it (in the shop) with the box upside down on top of it is fine.
Don't forget a PMV
Thanks. I have quite a few pieces to get. Plan was to make a list and lay it out and come here for verification. I had a question though, should I have 2 PMV's, one after the compressor, then one after the tower...or just a check valve after the compressor, and then a PMV after the tower?
Just so anyone who's following, American Airworks actually quoted me ~ $54.xx for the AC-94505 (I'm not sue what shipping would be). Filter Techs is $80 after shipping.
Edit: I was wrong American Airworks is $85.64 as of this posting, so the place linked above is cheaper.