Harpo had a long-term fixation on typography (collected samples of fonts, liked learning about type designers like Eric Gill and Bruce Rogers, etc.); that passed, in favour of a Northwest Coast art obsession, during which he liked discussing the differences between Tlingit, Tsimshian, Haida, Kwakwaka'wakw, Nuu-chah-nulth, and Coast Salish art; now he's mainly into maps old and new.
Groucho loves mediaeval history (he's especially into the Bayeux Tapestry, for some reason), and, his dearest love, recycling! Every scrap of possibly reusable stuff around here is pressed into service to become part of one of his "constructions"--sort of sculptures that he puts together out of cardboard and tin cans and so on.
Chico's turning into a card shark--he has a couple big books of card games, and he's always wanting to learn new games--it was whist this morning!
I love reading what all your kids are doing! I had friends with kids who loved Formula One and the East German railways, so a couple of the hobbies you're discussing are ringing some nostalgic bells for me!
peace
minnie
