Smart purchase, I can't wait to see the results!
All I know is 14th century bascinets were historically attached to the leather via some sort of heavy thread in the examples I've seen. This is the Lyle Bascinet in the Royal Armouries, and you can make out the thread sewn through the leather and then the upper most rings of the aventail.
I used the same method with some success as well as disappointment, most probably due to inferior materials and/or knowledge. The thread I used first was the Tandy waxed variety. After 8 total hours of SCA combat, the thread shredded (due to my inability to block a certain King's wrap shots
). I then used the Tandy synthetic thread which seemed to last a little longer, but eventually failed in the same manner. Finally I just wove the top row of mail through the existing thread holes in the leather band. This was a cheat, but I haven’t had a problem since.
You might want to pony up for some much heavier thread as shown in the photograph. It may be that this heavier thread will wear much better.
If you find a source, please let us know!