In a perfect world, of cars designed a century back, yeah the kingpin should be rim center, but then for proper loading, rim center should also divide the plain of both wheel bearings, about 50 years after the kingpin rule...
But as we all see today on various builds, the king pin, for performance orientation id usually inboard of the rim completely. The amount of inset can also be used to exaggerate ackerman, and on many straight axle, oval track cars was for years. The inside spindle would be longer than the outside with the rim spaced further away than the out board rim. Lots of trial and error, from the 40-70's.
It's not going to be anything special, but we'll get together somewhere this fall, and you'll be more than welcome to try 'er out for an hour or 2.....long as you put a set of wheels under me too....LMAO!
Yeah, I've known some guys that "gap" too. Just seems counter productive to going for a good fit in the first place....