It sounds to me like one of your shoe linings has delaminated from the shoe and is causing brake jamming issues. This is likely caused by driving with the park brake applied and overheating the shoe. The 7FGCU15 uses the 4Y engine and is very powerful. THe operator may have inadvertently driven with the brake on without knowing it. Either way it is a good idea to remove the drums and inspect the problem on both sides. Not including travel, the time for inspection should be less than an hour. If the drums are not scored you can replace the shoes in another hour to hour and a half. A sharp mechanic will have the whole thing up and running again in 2-3 hours. Dealers typically charge around $90-100 / hr. Independants are around $60-80 / hour. A tip! Save yourself the hassle of aftermarket bargain shoes and use the Original Toyota shoes. You will usually get double the life.
HG