It seems most older basses that have undergone restoration have had the bass bar replaced. What is it that necessitates bass bar replacement? Does a bass bar 'sag' over time? Does it lose its ability to adequately support the top? Or is it a matter of needing a larger, stiffer bar to withstand the tension of steel strings? My Czech bass ('20's- '30's vintage) is showing signs of top sinkage at both ends of the bass bar. It definitely needs a post patch, should it also have the bass bar replaced? If so, should the top be cast and pressed back to its original shape first? I'm sure the reshaping procedure would be expensive, and as much as I love the bass I don't know if it would warrant such an investment. It still sounds good, with no buzzes. Should I just not fix what ain't really broke?