if you opt to fix disclose it was repaired.

if someone grabs the railing in the future and it breaks apart
somewhere else, you wouldnt be liable.

its easy to replace that railing 5 minutes with a propane torch will
get all the paint off the bolts, the parts in concrete are cut off and
taken out piece by piece, epoxy concrete sets the new posts securely.

years ago i tried a patch like your talking about, my mom came out the
door on a very windy day, lost her balance, grabbed the railing and
fell 10 or 12 feet, railing broke apart. luckily she wasnt seriously
injured, i was right behind her and watched in horror as she
disappeared in the dark.....

fix railings right or leave them be................