A: It's tough to get a firm answer as to when there was lead paint used on Matchbox cars and when the practice stopped. So, I asked Mattel (which owns the brand) if they could shed some light.
"As you are probably aware, standards around children’s toys and paint went into effect in the U.S. in the 1970s (I’m not sure about the timeline in the UK, which is where Matchbox originated)," Mattel spokeswoman Jules Andres wrote in an email. "Mattel acquired the Matchbox brand in 1997. Additionally, the standards were revised as recently as last year in the U.S.
Mattel's advice is sound. What you suspect might have lead is probably best to stay away from.
If you want to go a step further, you could have the cars tested. Some non-profit safety groups offer x-ray flourescence testing for parents who want the same answers that you do. Or, if you have the money and the inclination, you could also pay a private lab to test a sampling of the cars. The testing will likely far exceed the value of each car, however.
The best bet is save those cars to give to the kids when they're old enough to not put them in their mouths and can appreciate that they're something from their dad's childhood.