Hope this explanation will help a bit....
When we insert a 9-pin 6DJ8 or 6BQ7A into a 7-pin adaptor, we have the following:
Tube pin assignment -> unmodified adapter -> Little Dot pin-hole assignment
Tube pin 8 (cathode) -> pin-hole 7 (screen/suppressor grid)
Tube pin 7 (grid) -> pin-hole 6 (screen/suppressor grid)
Tube pin 6 (plate) -> pin-hole 5 (plate)
Tube pin 5 (heater) -> pin-hole 4 (heater)
Tube pin 4 (heater) -> pin-hole 3 (heater)
We are fortunate that tube pins 4, 5 and 6 line up perfectly. However, we are not so lucky with tube pins 8 and 7. The Little Dot assigns the grid to pin-hole 1, not pin-hole 6; and the cathode to pin-hole 2, not pin-hole 7.
So we modify the adapter. We connect tube pin 8 (adapter pin 7) to adapter pin 2 to reroute the cathode to pin-hole 2, and tube pin 7 (adapter pin 6) to adapter pin 1 to reroute the grid to pin-hole 1.
Now that adapter pins 2 and 7 are connected and pins 6 and 1 are connected, we do not want pins 6 and 7 to extend out of the bottom of the adapter and into pin-holes 6 and 7 in the Little Dot socket. So we cut them a bit short. When you look at the bottom of the adapter, you will see only 5 pins, as the other two have been shortened.
Hope this helps.
PS: Very frankly, it was quite a struggle to put my adapters back to together after modification, but everything is working perfect. Therefore, I am very reluctant to take them apart in order to take pictures as I don't want to risk breaking them somehow. (>_<)