for age, various US companies recommend replacing tires at 6 [Ford] or 10 [tire association] years - for light vehicle tires there is no legal requirement, the date codes are for manufacturer warranty purposes - transport operators, particularly busses, do limit the age of tires, but I've never found any legal requirement for it - tires should be replaced when they show signs of deteriorating, like UV chalking and cracking
back in '69 when they were still uncommon in the US, radials normally used tubes, the proper type of tubes, which no doubt is what any tire dealer would supply today - if tubes in tubeless radials were illegal and unsafe, they
wouldn't be marketed 
code TL means tire
can be used tubeless, code TT means tire
must have a tube
Bill
