Ian--I've got a couple of 19th century tambourines (photos are posted on my page). Both have a brad or piece of thick wire that is passed through the bottom of the rim, through a slot cut to accept the jingles, and back into the rim above the slot.
Of course - Right up through the bottom! That's the piece of information I was looking for. Perfect (and totally obvious - now that someone tells me!) . Thanks Rob.
Gotta love tambos... basically hand held frame drums. Need more drums in our playing, definitely. :)
Hey Ian, You should take your finished hoop, make or obtain some nice brass jingles, then mark out four or five rectangular jingle slots with a pencil a bit closer to the open end than to the end where you want to stretch the head. You can use a drill to make holes at either end of the slot, then a hacksaw to cut them out. Don't make them too wide as it will increase the amount of jingle sound and limit controlling them, but not so tight that you can't get a nice shake roll from them. Drill another hole with a tiny bit to put your jingle post in, which can be an ordinary nail. A little glue will help keep it stable. Best of luck!
Thanks for the tips