I am repairing an old mandolin I made. It developed a crack in the soundboard, probably because a brace came loose. I have removed the soundboard, and the braces, and repaired the crack. I'm wondering if I should change the bracing pattern from simple transverse to maybe an 'A' shape, to give it more strength. Another factor is the fact that the wood (sitka spruce) is only 2.2mm thick. Is that too thin?
This is the original bracing...
and here is the partially repaired soundboard
I know it looks a bit of a mess, but I have to decide between keeping it intact as an old and loved instrument (made in 1976) or adding a brand new soundboard. If it can be used, I'd like to use it, but if it's too thin now, then so be it.