Oldfordguy,
The body of the Sears buggy that I have is plastic but as for the dolls go, yes, the size seems to be proportioned to the size of the Barbie dolls that my sister has also. My older brother use to put my sister's Barbies in there just to watch them fly out when he would jump ramps. Can you e-mail me a picture of your tonka truck. I'd like to see how close it is to the look of mine. My email address is dani9678@bellsouth.net
Thanks,
Matt