The body has sunk on my mandolin between the sound holes. I took the old strings off and cleaned it and started to restring it and the bridge was pushing down. I didn't notice it until the strings started snapping.

Check these sites out....

https://www.google.com/search?q=attaching+bridge+to+gutar+body


Best to you.

Have you put strings through tuning heads and folded them back on themselves and tightened them up to standard tuning?

On the Hofner Shorty, you will need to manually remove the bridge with a screw drive or similar tool. There are large screws on either side of the bride that when removed, the bridge will come off entirely. At this point, you can unwind the strings from the tuners on the head of the guitar, which will completely slacken the strings. Push the strings out the back side of the bridge to remove the old string, and insert the new strings via the same hole in the corresponding order they were removed. Make sure all new strings are looped through the bridge, then set the bridge in place. At this time, with all the strings hooked in and the bridge set in place, you can now attach the strings to the tuners.

Exactly as you would restring a Peavey Preditor EXP Regular guitar. Seriously, if you can, take it to a Guitar Center (or a real guitar shop) and get the technician to put down the donuts and show you. Depending on the bridge (several tailpieces are available in that model) it should cast you about $15 plus strings. Send a pic - I'll find you a procedure.

You can slide the silver plate straight back by gently pushing it from the top with your fingers. Once it slides off you will then be able to see the hooks that you put the new strings on (loop end strings). Once strings are tightened, you slide the cover back on the same way you slid it off. There is a small piece of felt glued to the cover. Be careful not to knock it loose when you are putting the cover on.

One other tip, change one string at a time instead of pulling all of them off at once. The bridge will come loose if you take all the strings off at once (it is not glued to the mandolin).

Check the neck to body attachment. There may be a problem there, especially if it has been strained in the past. The fact that the strings were so high when you got this would indicate there MAY be a problem with the neck attachment or the body where it attaches. Word of caution: Investigate how repairs are done on the instrument before attempting a fix. Using wrong materials can permanently disable an instrument. Banjos DO go out of tune easily, depending on how they are played. Another thing to remember is that strings are within about 10% of breaking when in tune on stringed instruments.

After getting the PROPER string, watch YouTube videos on replacing strings... guitar and mandolin are similar so you can watch either. Search "replacing string" and select video from choices.

Look near the near the highest string at the the silver part known as the bridge.There should be a hole right near the bottom of the thinnest string.Take the threaded end of the whammy bar and screw it in clockwise into the body.

You may be able to help this prob. your self. You will need a set of hemostats about 10 in. long. A nickel sized dental mirror a flexible LED light . First of all unstring it , put strings a side.Next look in side to the under side of the top of your Mandolin .With your lite and mirror you should see a spot where the post was org. placed.Now with your hemostats reinstall the post. Now this is like building a ship in a bottle, but it can be done , but just a little at at time. You need to lift up the whole top. Remember the top did not drope down all at once, nor will you rase it up all at one time. A little eack day untill you have reached a perpendicular point . One more thing, you post fell because the insturmant was to dry.You need to keep it humidfided . Take it to the shower with you. dont get it wet let it soak up the steam, it will help you get the post back up right and it will love you four it. Get a humidfier for it OK

Looking at your desired notes the mandolin is standard tuned to gdae.
So three of the four notes are already available, just put the "d" mando strings where the "g" ones would go and the "g" ones where the "D" ones would go the highest is already a "e" and I am sure the "a" would tune up to a "B" with little risk.
You can also look at string sets made for the madochello or possbly octave mandolin.

Good luck,

The dude.