Restoration of French bass

[Dave Whitla]

Hello everyone. I have a question on behalf of myself and my luthier!
My old French bass is currently undergoing a fairly significant restoration of the top. I’ll attach a ‘before’ photo. It has been re-arched in a cast, and a large number of old cracks, cleats, patches and straps are being removed and redone, including chest and soundpost. The bass bar, which had been sprung too hard and was actually cracking the top from the inside, will be replaced (and not sprung). There was a lot of woodworm damage, around the lower end of the center seam and bass bar particularly, which had been “repaired” using epoxy . This is being removed and new wood patches inserted. The restoration is being done by Tom Barrett and I feel that he is doing an excellent job.

Most of this work is nearing completion (second photo), which leads me to my question. There will be three larger patches covering the width of the upper, middle and lower areas. Obviously this will make the top thicker. What Tom and I are looking for input on is how should he approach the graduation of the top once the overall work is done. I don’t have all the measurements from before the work was started, but the top was quite thin in many places. The center of the top was about 10mm. The bass was cut down at the upper shoulders at some stage, so aiming completely for the original graduations is probably not the way to go, even if we knew them. We have decided to realign the bass bar slightly from its original position to accommodate the ‘new’ dimension of the top.

I would like to keep the beautiful, dark sound this bass had before as much as possible, but I would also like to return it towards what it might likely have been 200 or so years ago. Any input would be greatly appreciated.