Those are for a different series of AM Planetary Gearbox, I believe. In fact, you don't even need the adaptor plate, the PG27 is built to accept the 9015 (among others), no additional hardware needed (except the pinion).
If you want a 9015 motor on a PG27, they sell it
here.
We used these on our intake this year, and were very happy.
But before we succeeded, we attempted to pull the pinion gear off of the 775 motor that was installed in our PG27s, and succeeded. But when we pressed it onto the 9015, it split in two pieces. After all, it is "formed from powdered metal."
After a lot of searching, I found
this, which is the pinion that you need. It was not under pinion gears, but instead under planetary gears.
Hopefully someone will make this more clear on the AM website; a link to the
correct pinion from the
PG27 page would be extremely helpful and reduce confusion.