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I have an old Kay mandolin that was given to me.

For the tuning machines is it possible to make or purchase replacement buttons, or am I better off replacing the entire tuning machine set? For the wide crack on the top should I splice in material? I think the gap is too wide to try and pull it back together. Finally, what are the recommendations to align the sides it the top and back? Notice the mismatch.

rcnewcomb wrote: ↑Sat Apr 11, 2026 8:18 pm I have an old Kay mandolin that was given to me.

For the tuning machines is it possible to make or purchase replacement buttons, or am I better off replacing the entire tuning machine set?
IMG_9851.jpeg IMG_9852.jpeg

For the wide crack on the top should I splice in material? I think the gap is too wide to try and pull it back together.
IMG_9856.jpeg

Finally, what are the recommendations to align the sides it the top and back? Notice the mismatch.
IMG_9854.jpeg

For the best answers to these questions, you might go to the "Builders and Repair" section of the Mandolin Cafe:
https://www.mandolincafe.net/home/forum ... and-repair

I've seen the individual buttons for sale somewhere, but the trouble is getting them to match the originals. If the instrument isn't valuable as a vintage collector's item, it's probably better to replace the tuners. That's if the spacing is the same. If it isn't (and there's no guarantee on older instruments, you might end up having to buy eight buttons and keeping the original machines.

I think I would splice in material for the gap on the top. If you can get some sort of adhesive, like glue-saturated linen or super-sticky tape, into the body through the F-hole, that would further reinforce that area to help prevent the recurrence of the crack.

I have no suggestions about how to deal with the mismatch of the sides and the top and back. However you do it, you have to solve the problem of what caused the misalignment in the first place.

Frank Ford has many tips on frets.com about this stuff. In the repair section there were tips on replacing tuners and this jig for getting the sides to realign, http://frets.com/FretsPages/Luthier/Tec ... ptest.html. Have fun!

I think I'd replace the tuners with some good modern ones, which will almost certainly turn more easily and smoothly than the originals. If you worry about keeping it all original, etc., just save the old ones in case you someday sell it to a purist. They can always reinstall them.
That assumes the hole spacing is the same on the old and new,, at least for the string posts. The small holes for the attaching screws don't matter as much. One can shift the string post holes too, but it's a lot more obvious.
The Stewart-MacDonald website (stewmac.com) has a selection of mandolin tuners, with dimensions,that you can refer to when trying to find a match.

As far as patching... First, make sure the mandolin isn't dried out. Stick it in a plastic bag with a wet sponge for about a week and see if that will close any of the cracks. A bit of persuasion with a clamp may help. Close it as much as it will go without being heavy-handed about it and glue a cleat or two across the crack on the inside. There are sneaky ways to do that when the only opening is an f-hole, involving a mandolin E string (or any small diameter string, the smaller the better) fed through the crack, the end fished out and a cleat attached, glue added, then pulled inside and snugged up against the crack. Cleats should be small with grain running, I think, at 45 degrees to the grain they're being applied to. It ain't easy.

As for adding in wood, I was advised to shape the hole to have parallel sides and rounded ends, the rounded ends being marginally less obvious than a rectangle with four 90 degree corners. Maybe.

Thanks for the responses. They are very helpful.