First and last step of quarter round carving
 
First and last step of quarter round carving

The left photo shows the carving of the 1/8" shoulders. The right photo shows the full chamfer and completed to the quarter round at the far right of that picture, enlarge to see it closely. The middle photo shows the fine shaving cuts made to complete the radius. Now, sanding! Yes, sanding. Cloth, hyde glue and grinding stone to the coarseness you want was going on for centuries previous. Hardwoods can be scraped but not white pine - too soft. Now, the slip joint tenon at the top of the arch can be glued only, for now. The muntins in the top must be measured, mortised and tenoned, coped and precisely fitted first before glueing those joynts at the door stiles. No room for error here, not after all this work. This is quite a lot of work for just one door. Stick around if you're not bored to death. > Arched moulding above the door.