Here are most, I think, of the Methuen codes given for PC10 in the Windsock Datafiles:
3E8, 3E8
4F2, 4F3, 4F4, 4F5, 4F6, 4F7, 4F8
5F8
30F8
Here are the majority of Methuen codes for PC12 from the WDs:
5F5
8E8
8F8
9E6
9E8
Per the link in the Methuen Handbook of color thread, 9E6 and 9E8 were most likely matched to AMAPDT that was thought to be PC12.
Stuart