Sorry for the late response guys. I'm Rob's friend with the original issue.

Mine had a 6 digit. It was odd because there were two empty spaces with the factory MPU and then just one space with the Altek... but still not well aligned.
Using the 7digit with the Altek produces the desired effect due to the tighter digit spacing, but appears its more of a hack/fix than proper.

Nice work on the wiring comparisons. I'll have to look at mine tomorrow to see which version I have.

I had bought a blue LED set of displays for it ages ago and so would love for it to work properly with 6 since that is what I've got and Xpin has since discontinued their blue displays.