I changed my mind on the guide and made something more robust from a scrap of 2x4. Some shallow cuts with a backsaw pressed against the sloped face of the 2x4 made the step. Then some shaving with the thumb plane and a chisel started to smooth the curve of the bonnet. Finished the shaping with rasp and wood file.
Then sanded it with 80 grit.
After doing some more sanding on the body I realize it has to go to the body shop to repair a dent in the left door and a hole in the left rear. The cheap Black Walnut I have is the core of the tree and the central ring has gone punky.
I drilled out the punk.
And made some Black Walnut dowels to fit.
Then glued in the dowels using a paste of white carpenter's glue and Black Walnut sawdust to camouflage any gaps around the dowels.
A spoon chisel and the thumb plane cut the dowels down flush and a little sanding smoothed them into the surface. I'll ignore the big punk scar in the wheel well, it will be hidden by the wheel.
There has to be more shaping to the front of the bonnet, the radiator top is more round than the shape I have now. It looks like I have to round it in to meet the rad but the drawings show the bonnet with straight lines from the scuttle to the rad. If any owner of a circa 1950 Morgan has the solution for me drop a note to:
Meanwhile I'll turn my attention to the details, like cutting grooves for the side trim etc. And I need to revisit the windscreen dowels, the ones I made for the repairs were far better than the one for the windscreen.