Long ago, I used to go to a luthier who was fond of a technique he called "sealing" a bass. When he had an instrument he either wanted to use himself or put in a good amount of time to set up well he would do this: When it was time to glue the top on, instead of merely clamping the top after applying glue, he would painstakingly sand (or carve, I can't remember) the parts of the top table that didn't line up perfectly with the ribs(I may have that backwards, with the ribs being altered instead). So when it came time to glue the top, the top sat on the ribs without any gaps with a minimum of pressure, with something like a book on the top to set up the gluing. The purpose of all this was to have a bass that was to avoid undue tension in the top table and have an instrument that played very easily. He never used an adjustable bridge on a bass set up this way. Has anyone else come across a procedure such as this?