There is at least one that came with an older set and it may in fact be the one you pictured. It would be interesting to know which release is the oldest. Have you browsed Mr Ripleys Plarail Catalog collection? I always thought this design was reminiscent to the 1950's-60's style cars.
What a coincidence, I just was browsing the Auctions in Japan and saw this Listing with another release, this one is the #51. I think there are some differences in the shade of blue on these different releases and I think that the lightest shade may be the oldest. https://www.jauce.com/auction/j470875281
![[Image: ozibb712764.jpg]](https://s10.postimg.cc/icf21vac5/ozibb712764.jpg)
What a coincidence, I just was browsing the Auctions in Japan and saw this Listing with another release, this one is the #51. I think there are some differences in the shade of blue on these different releases and I think that the lightest shade may be the oldest. https://www.jauce.com/auction/j470875281
![[-]](https://www.blueplastictracks.org/images/collapse.png)