sorry for the abruptness, but i don't like to play the telephone game of internet to customer to mechanic.
the drum system is pretty basic and sussing out such a glaring problem should be fairly straight forward. it might take some money and a few swings and misses on parts, but that's a risk you have to be willing to take with old cars. if you mechanic isn't super knowledgeable with older iron, you both might be better served in taking the work elsewhere.
personally, i wouldn't spend a dime on drums and go straight to discs.