Ah sorry, I mixed up the words... I meant "reassembling". It definitely helps with old cars to tear them down, clean (and repaint!) everything, replace all worn-down parts and then put it together again, without going as deep as re-boring cylinder holes and inserting new pistons - that one definitely requires a skilled expert as well as specialized tools, while all you need for a disassemble-cleanup-reassemble can be done at a hobby garage or in your shed if you have a sufficiently large shed and a well sorted toolbox.
