Actually the one that Squelchtone has in his signature is the 833 I believe.
The one being shown in my video is the 951, the model features a better cast with less shrink holes. So I assume they have put some more effort into the casting technique. I do not know if they have changed the material though. The anti drill rods should be the same, also the ceramic block down in the core hole should be there on the 833. I do not have the 833 yet so I was not able to do a comparison yet.