When you say you don't think that pedal car is very old, just how old (or new) do you think it is?? Personally, if I had the room, I'd probably keep that one. It certainly has appeal!! However, I wold also have to invest a little elbow grease and $ to spruce it up a bit. All the rust is very distracting, IMO. But if not keeping, then I wouldn't touch it!!
As for your Michelin finds, that's a bit harder to nail down as far as collectibility. I never make it a point of knowing what "other" people like, but I know that there was a time when Michelin items were in great demand, as well as Goodyear. Now, I don't even know if racing stuff in general is very collectible. My question is, what makes you think they're reproductions? I'm sittin' here looking at the one with the "99" on the tag and, first off, trying to figure out what it is he's sitting on. However, it looks to me to be from the 60's or 70's, maybe. Same with the motorcycles.
Looks like you did pretty well. However, the real test will be in seeing what your return is on these investments.