Hello again guys.  I'm having an extruded cut dilemma with a part I'm trying to model for a guy in the shop (he came up with a design for a triangular birdbath and would like to see it modeled in 3D to see if he likes it).  Basically there are 3 vanes/sides each coming off a base triangle to a top triangle (both having parallel sides).  Their edges will not mate however.  Then at the top (after the 3 steel vanes are welded perpendicular to the base),  he will drop in a sheet metal formed triangular pan (which I haven't thought about yet but figure I can model that separately then drop it in to get the extruded cut in each vane to secure it at a specified height).

Anyways, my problem is this.  I have all 3 sides extruded mid plane off centerline of the triangles at 19" (the screenshot where they are all intersecting, tomoriginal.sldprt).  When I make a plane on centerline coincident and perpendicular to one of the sides of triangle) and go to make my extruded cut on just one of the vanes (screenshot with only one showing the profile cut and the other 2 at 1" wide, tom.sldprt) it will get to where I want it (if the other 2 are extruded at say 1").  But if I keep all 3 vanes at 19" extrusions mid plane, the cut feature will make cuts on the adjacent side vanes as well which I DON'T want.  Is there a way to just specify to make the extruded cut on a selected side?  I tried all the options (up to next, up to surface, etc) but none apparently will give what I want.  I need to take the screenshot and make all 3 sides the same, matching that profile.

Bottom line:  I need to somehow copy the extruded cut from the one vane (with profile cut, screenshot tom.sldprt) to all 3

Thanks for any advice!