Hey, Bob; welcome!
I'm surprised your jigsaw didn't just zip through those like butter. Perhaps too fine a blade? A router will require multiple passes to cut all the way through. Personally, I'd cut out the holes, leaving maybe an 1/8"+ waste, then clean up the cuts with a straight bit and a template. Your router has a plunge base?
Don't even think about doing this without working out a secure clamping arrangement...obviously the work will have to be raised above the bench as both your jigsaw and router bits will be coming thorough the bottom of the work-piece.
Since all the pieces are the same size, how about building a frame of 2x4 on the flat, with a rebate on the inner edge that will allow the work-piece to just drop in...maybe 5/8"x 5/8" ? If the front piece extends out both sides, you could just clamp those tails down, assuming the frame is screwed together.
I'm surprised your jigsaw didn't just zip through those like butter. Perhaps too fine a blade? A router will require multiple passes to cut all the way through. Personally, I'd cut out the holes, leaving maybe an 1/8"+ waste, then clean up the cuts with a straight bit and a template. Your router has a plunge base?
Don't even think about doing this without working out a secure clamping arrangement...obviously the work will have to be raised above the bench as both your jigsaw and router bits will be coming thorough the bottom of the work-piece.
Since all the pieces are the same size, how about building a frame of 2x4 on the flat, with a rebate on the inner edge that will allow the work-piece to just drop in...maybe 5/8"x 5/8" ? If the front piece extends out both sides, you could just clamp those tails down, assuming the frame is screwed together.