egalsim

Just re-read the OP. The original Optima is basically a 2wd buggy with 4wd. It uses a rear motor configuration and will be better suited for actual off road conditions with loose traction. Comparing that with the 870c, which I would consider a "2nd" generation 4wd racing buggy i.e. Optima Mid, Ayk Radiant, Schumacher Cat etc... is totally different. The orignal Optima was made to be "cool" first and performance a close second. With that being said, the Javelin (Roll cage version of the Optima), is the greatest RC car ever made, as it was also designed by Akira Kogawa, the greatest RC Designer ever.

If you are going to race the car, the 870c will be the better choice. It is far easier to work on, especially when getting to the diffs. The Kyosho, however, will be a great DURABLE car for bashing, or even displaying on your shelf, it is also great for racing, however, working on it might take a little more patience than the Yokomo. I have both. I find that the plastic and build quality on the Kyosho is better than on the Yokomo, this is comparing the re release of the Optima Mid and the re release of the 870c. Made a couple videos for each car.

2022 Mid is a GREAT choice. If you ever plan on racing it and need 2.2 wheels, JC Racing makes pepperpot 2.2 wheels for it. I love my 2022.

Here's how I did mine:

Scorpion wheels DO NOT FIT with out modification. I used some old CRP wheel nuts from a Tamiya to 12mm hex conversion kit as well as had to drill out the center hole CAREFULLY to make room for those long wheel nuts. I think to do it properly, you may have to buy rear drive axles for the Scorpion and use them instead of the Ultima axles. I was basically lucky that I had the CRP nuts tp do the conversion. You also have to sinter the 12mm hex to replicate the friction of the Scorpion circular wheel hubs. Yes, I make videos on stuff I like on Brown Neck Reviews, Thank you!

SWB chassis IS for the Original Optima Mid SE. The Turbo Optima Mid Special, Optima Mid Custom, and Optima Mid Custom Special are long wheelbase. LWB chassis are also saddle pack configured, not the narrow version like you have in the pics. The Optima Mid, Turbo Optima Mid and Turbo Optima Mid SE are short wheelbase and chassis is interchangeable between all the SWB versions. I am running a Re release chassis plate on my original Optima Mid. The Re release Optima Mid chassis plate looks exactly like the one in your pics, except more silver in color.

The re release chassis will work, along with almost any short wheelbase Optima mid chassis. The Mid SE bottom plate was basically a Optima Mid chassis with countersunk screw holes. Hole placement is the same. I just put a rerelease chassis plate on my original Optima Mid.