Strangely enough, today, after having the 335is cluster in overnight and starting it up in the morning, the tach needle worked. A few seconds later, speedo jumped up and worked as well. All errors were also gone! Cluster didn't think it was in a vert anymore lol. About 1/2 hour later, once I revved the engine a bit, the engine temp worked as well!
Now I've got a fully working cluster that seems to have programmed itself to the rest of the car automatically. I'll try programming with NCS a bit later but suspect I'll get the same error as above.
Currently loading files needed for winkfp to program the correct VIN and VO to the cluster. Once that's complete, a tweak in production date within NCS (cluster was mfg. 5 years after my original cluster lol) and I should be able to program all features. Will update 1st post with a step-by-step guide if I do get it programmable.
Now to open it up and get that nasty '335is' lettering off...new faces and needles look cool though