Scantiling of a plywood/epoxy keel stringer

14 ft x 5.5 ft tiller power skiff, v into a rounded almost flat bottom (a seaswirl P-14 from the early 60s) I an rebuilding the stringer that runs down the center, original is long gone.

I have some 4ft sections of joubert 1/4 inch marine and a nice 12 ft clear Doug fir that is 1.5x2 actual. Stringer will be from 3 inches to about 8 inches tall along its length. Plan is to cut 3 sections of plywood, lay them along the fir and epoxy them to the fir which will be a clear. Then glass both sides of the ply, set the keel in epoxy putty, fillet to hull and tape along the length.

Should I also butt block the ply sections?
If so, any reason the but block couldnt be added over the first layer of glass? Avoiding the bump and having to smooth that out would be the idea. Butt block both sides? I guess I could practice my scarfing with the 1/4 inch. Or is it too thin in the first place?

 

I gotta admit, not following this plan at all.

A small 1.5 x 2" piece of doug fir and some 1/4" ply doesn't sound like much of a stringer and would need a bit of glass to make it strong. Was the first going on the top or the bottom?