hum,
i would vote for welt or lacing....
reminds me of the Legcut bowman i had ......Keith Siedel told me it was "possible" to cover it without welt or lacing (see one of his legcut bowman covered without welt)
I can tell you = i tried , failed and gone at last for the welt.....
i guess you can do it if your piece of leather is really really really stretchy .....and even though....not sure it would do
Good luck
and do not forget :
If Plan "A" did not work....the alphabet has 25 more letters ...so stay cool"
:D