PORT LAVACA, Texas—Weapons buffs may stock semiautomatics in the gun safe. But nothing makes a statement like having an Army tank in the garage.

Scattered around the country are members of a small fraternity of guys who own tanks. They are hyper-avid history buffs or hyper-edgy investors or just wealthy men who can now afford hyper-sized versions of the toys they played with when they were boys. Tank brokers—yes, there is such a thing—estimate there are several hundred to 1,000 private tank owners in the U.S.

"There's always a little boy in the man," says Barbara Bauer, whose husband, Bill Bauer, owns a pristine, 20-ton, World War II Chaffee tank in Port Lavaca.

Mr. Bauer, the 70-year-old chairman of First National Bank in Port Lavaca, stores his Chaffee, a pair of armored half-tracks and other vintage military vehicles in a climate-controlled warehouse, where his four-man team of mechanics keeps them in showroom condition. On Veterans Day he takes the tank out for the parade, but mostly he just likes to admire it and preserve it for the next generation of history fans.

Brothers Ken and Gene Neal, owners of Bullet Proof Diesel, a truck-parts manufacturer in Mesa, Ariz., once took their 1966 British Chieftain tank into the desert and joyfully drove it over a rusty car, with the turret facing backward.