In the last weeks I've followed with interest the evolution of your dock rings and, while I'm still not convinced I want to change the default ones (I don't think they're very bad), I've decided to give it a try, so here's my idea. :)
First of all I'd like to celebrate with one minute of silence my loved 856 Bulldozer (I guess in US it has a different number) because I had to mutilate it in order to get some piece. :P
Second, please forgive me for the bad images (my iPhone 6S is getting really old) and for the rainbow color of the pieces: I didn't have the most I needed so I had to improvise with what I had.
Ok, let's start:
I went with a 10 sides polygon. Not because I wanted exactly 10 sides but... well, it's what came out after one hour of efforts:
While the construction is very delicate, once mounted it's quite sturdy (but still not good for play). What I really cared of was to have the inclined plates.
The gap between the ring and the "body" can be minimized adding some plates or rings; I didn't change the original Lego design at all (forgot). :)
Here you can see the wheel of the bulldozer. :)
I've chosen this method to leave plenty of space for the inside greeblings of the ring. Later on this topic.
This is the heart of the concept. Here's how it works:
The light tan is the plate, the dark tan should have been 1x3 but I didn't have, so ignore it. The gap between the 1x2 brick and the rest of the structure is to keep it anchored to the tracks. Also ignore the 1x2 brick with hole, it's not the correct piece, but it's a pic from a previous version. The correct pieces are two 1x2 plates, as you can see in the previous image.
Anyway, this way the 1x3 plate goes "inside" the track and it's kept secured by the rear brick (plate).
Here's the result, seen from behind. Very colorful! :)
The inside (front) part of the ring can be connected in various ways, for example here I'm using an axle:
I didn't work on this detail because I think @Neophyte_brickie solution, that I love, could be adapted without any problem.
This is just (a part of) the original lego inside ring, as example:
Of course a round plate could (and should) cover the parts below the external plates.
I think it's also possible to implement the nice "corner plates" as in the rendering of @Vouatch, to make the external ring more similar to the real thing; unfortunately I didn't have any of them.
Well, maybe it still need some small improvements here and there (and a wise choice of colors to minimize gaps) but I think it's not bad. Should I change original ones I think I'll go this way; or something similar. :)