I just acquired a large frame 45-70 this past weekend. I went on e-bay and searched "Bullard Rifles" and it came up with books written about the rifles and an article on disassembly. They are very well made rifles with only about 12,000 produced. They were offered in both single-shot and lever action configuration.
My brother has a Deluxe one in 50-115, i had a real nice one in 45-70 that i sold my nephew. i have worked on the one i had ,rack and pinion bolt setup ,very well made. Heres the one i had. Don