I just did my upper and lower boot and found it to be pretty tough to push my flimsy mounting ring back into place with the new leather boot. Especially at the seems, it was hard to apply enough pressure by hand to get the leather to seat in the groove in the ring.
Using this wooden clamp to expand the ring as I was aligning the holes with my awl made it really easy. The ring practically fell into place and was lined up perfectly for riveting.

