This is a rather nice Kit, not my favorite one though.
The SF3D Kits been around for about 20 years now. Kow Yokohama who did the designs did also all the early Zoids Designs.
The reason for the designs is explained in the SF3D history, it asumes that Germany won WW II and that not much new technology was invented after that.
And, yes, they were kitbashed hence the liberal use of Motorbike parts too.
The Kits weren't available for a long time due to a licence dispute between Kow Yokohama and Hobby Japan, HJ owned the SF3D name while Kow Yokohama owned the designs a few years ago Kow got permission to re-release the Kits under a new name.
The Kits are still original with a few changes to decals and packaging of course.
In the meantime there have been a few other Companies adding Resin Kits of original previously unreleased designs or offering conversion Kits.
I got into them when they were first released and at that time they were mindblowing considering that they featured lights, wires and simialr parts, even by todays standard they are still very good kits and well worth the buck.
Pity, is that NITTO is not issuing any of their non-SF3D kits anymore.