It is so important for the well being of your battery, and even the surrounding area, that all anti vibration rubbers are replaced regularly.
If they degrade or become damaged, particularly after removing and refitting, perhaps during the restoration process, a cracked battery body through excessive high frequency vibration, can lead to the most appalling corrosive damage when sulphuric acid leaks onto the surrounding chassis!
Buy your new one's on line now, it is much cheaper than that horrendous alternative!