What is a big gift I could give to my dad for Christmas?

My parents have had a really tough year and so I wanted to get them something more than just a trinket or money or a gift card to their favorite restaurant. For my mom we bought an antique china cabinet that my dad is working on refurbishing and then we have bought or are in the process of buying Royal Doultan figurines for it (something she could never afford to splurge on when we were young). I have bought one to represent myself (as my name doesn't exist), her name figurine, her birth month, her favorite season, one to represent my younger and older brother and a romantic one to represent her and my dad. On Christmas we plan on bringing the cabinet out once she's asleep as both kids will be there for the week and then filling it with the Doulton boxes all wrapped up! Because we're doing such a fancy thing for my mom, I wanted to do something big for my dad! He doesn't drink (AA, sober a year and 7 months), he's an RV repairman so he already has every tool in the world and doubles of the major ones. So I'm out of ideas and so is my mom. Anything anybody could think of anything major like the gift we're doing for my mom?