You can also forge an
Elixir of Life, which, like the Boots of Youth lch mentioned above, won't actually reduce your unit's age, but will prevent aging/afflictions due to aging. The elixir goes in a misc slot, in case your chassis doesn't have feet slots.
If you happen to be playing T'ien Ch'i, you also potentially have the options of
Internal Alchemy and
Thousand Year Ginseng