The fact that the end pin isn't centered over the seam in the end ribbing does not in itself imply that the hole needs to be moved.
I have looked into this, and I understand that the most important things are that: 1) the strings are centered on the fingerboard, 2) the strings are centered on the bridge, 3) the edge of the bass foot of the bridge overhangs the edge of the bass bar by 1 mm, and 4) when (1), (2), and (3) are true, there is little or no sideways tension on the bridge that would tend to cause the bridge to move sideways on its own.
So the seam may be off center while the hole is not off center.
Howdy Lullyfan ,
I think we may have talked about this before ...
Pierre has givin you the information you need ....depending on pin angle and centering as to if anything is to be done at all ...
When I see specs posted it makes me cringe a bit ....bridges are not all the same nor are violins ...bridge feet may be from 11 1/2 mm to 15 mm in length so you can choose one that places it's feet where the sound is best for your fiddle as bass bars are not placed the same in all fiddles as well ...
Best to rely on information from professional luthiers as well meaning folks that post here may or may not have on hands experiance ...at that , I still recomend at least three pro oppinions as there are differant schools of thought and training ...
If you're talking about a $75 fiddle and a luthier may fix it while you wait for $25 then repair is a matter of putting more money into it or saving for yer next upgrade ...
My claim that the bridge foot should overhang the bass bar by 1 mm comes from some threads on maestronet, wherein four or five experienced luthiers asserted it in the same context. I've seen it elsewhere too, and haven't seen contradictions to it. No doubt there are some hidden assumptions regarding the models of violin and bridge, but it seems that no one there thought they were worth mentioning.
So there's your three pro opinions and more.
For the bridge blanks I've seen for sale, I don't know that I've seen any spec other than "4/4 violin bridge" or similar. They are going to be 41 to 42 mm wide at the feet, and that's what matters.
Also, Lullyfan has the same model violin as I do, and I find that mine is set up consistent with the 1 mm spec.