This is a post by user "hellnbak" in a topic on the SketchUp forum here
It's following on from some amazing 3D modelling he did in 2012, which is posted at the start of that topic.
After doing that (and having to guess some details, he came across some photos of the Hannibal 8 being restored at Stahls Museum, and added this post to his topic:

by hellnbak Mon Dec 28, 2015 6:00 am

Was doing some research for a new model and happened to come across some new photos of a Hannibal 8 being restored. Couldn't figure out how I had missed them before, but then I noticed that they were posted to Flickr about 9 months after I posted my model. Figured I'd post them here in case anybody wanted to see what the Hannibal 8 really looks like in some of the areas where I had to use my imagination because there were no reference photos available at the time.

This is what my less-than-stellar imagination came up with for the hydraulics, chain drive and whatnot

and here's what it actually looks like

The caption under the photo reads

Some more photos

Could have made the interior more accurate and detailed if I had had this photo

Didn't know all this stuff was in the back seat, I assume it's for the hydraulics

As you can see it's in pretty bad shape, but I did some searching and came up with some photos of it after being restored. As you can see the restoration is not complete, some parts are missing, such as the nose cone, spare tires, luggage, the pole holding up the roof, one of the rear wheels, etc. But it's definitely come a long way.

Apparently the guy standing at the control raises and lowers the vehicle, a real step up from the other Hannibal 8's on display elsewhere that are static and held up by poles. Also, this is the only one that got it right as far as the fenders raising with the body, like they did in the movie.

Anyhow, just thought I'd post these here in case anybody might be interested.
Am I gonna update my model with this new info? Probably not :|