The arch on the video uke is quite high, thats why the bracings and the linings are more sturdy than I would do them today...As the twine is applied it forms the arch and glues on the back all in one go.... I've just done some rough calc's, and with a high dome of 3/8" it would need about .025" sanded off the edges to fit the angle flush...less than a 1/32" or(0.6mm)...would they have bothered in 1917 or just let the glue fill the gaps??? can anyone on the Islands remember???