For those who requested a drawing/picture of my dust collector mod, it is on "alt.binaries.pictures.woodworking." under "dust collector." It is offered, rough as it is, in the hope that it will help.
For those who suggested upgrading to a larger unit, two things: Some of us are restricted to 120v. Also, the cost is actually much greater, if you have an existing dust collector.
For those who asked if this were not just making a single filter bag system into a two bag system, as you will see, you were "spot on" as the Brits say.
Deb