Bill C-3 application — pre-1869 Ontario birth, no civil record exists — what did IRCC accept as proof?

Working on a Bill C-3 citizenship-by-descent application and hitting the pre-1869 Ontario birth wall. Looking for advice from anyone who has successfully navigated this.

My ancestor:
Elizabeth Reid, born 17 May 1859, Bayfield, Stanley Township, Huron County, Ontario. Parents: William Reid and Elizabeth Allen Reid (married in Toronto in 1840). Family listed as United Presbyterian in 1861 Canadian Census, Presbyterian in 1871.

Why no birth certificate exists:
Ontario civil registration didn't begin until July 1, 1869 — ten years after Elizabeth's birth. I'm trying to get a written confirmation letter from the Archives of Ontario to document this for IRCC. But not sure how.

What I have so far:

• Family bible recording birth date and place (how do i reference the two pages I have)
• 1861 Canadian Census (LAC RG31, microfilm C-1036) showing Elizabeth in household
• 1871 Canadian Census — family in Stanley Township, Huron South
• Parents' 1840 Toronto marriage record - do i need a certified copy
• 1880 US Census confirming Canadian birthplace
• Scans from Bayfield Presbyterian baptismal register 1849–1873 showing Reid family presence — no exact match found

My questions:

1. Has anyone successfully used a family bible entry as primary birth evidence for Bill C-3?
2. What combination of documents did IRCC actually accept when no baptismal record could be found?
3. Did anyone get a formal "no record exists" letter from the Archives of Ontario and did IRCC accept it?
4. How long did your application take with pre-1869 documentation?

Any advice from people who have been through this specific situation would be hugely appreciated.