You may have this already but the following link has great information on plating of these stamps. You stamps also have an interesting right side in which the right frame line takes the place of the inner line.
http://stampsmarter.com/features/SQ...Plating.htmlI cannot point you directly to the answer to your question but I am confident a drill down within this webpage can get you there and provide great insight into these stamps as a whole.
Update: If you search by variety # in the link above you may find that Variety Number 9 matches your first stamp but make sure to check things carefully to confirm.
Hobsun