A post script on postage - and yes, I know the subject has been beaten to death.
I took my f8s to the post office yesterday. All were in legal size envelopes. I asked the clerk to hand cancel them. She checked weight. The Canadian envelope went for $.85. The US envelopes she considered first class packages and charged $1.95 each. They were prepared in the same manner as some I received which had only $.45 or $.65 postage. So your post office personnel make a big difference. This happened to be the postmaster, who is a stickler for details. If anyone gets my envelope and needs to pay more postage, let me know!