Dan, buy the book +1. You will never regret it. Contact El Numero Uno for a copy. So much info. I have one in soft cover in tatters from reading and rereading it so much.
I have more than a passing interest in the 45-70. My list to chase is as follows. others can chime is if they know of more.
45-70 BHS 22" medium weight barrel with sites, non prefix serial
45-70 BBS 22" medium weight barrel with sites, non prefix serial
45-70 non prefix in any configuration not listed above (not sure they exist but I still look)
45-70 1S 22" medium weight barrel with sites. Non prefix checkering, no warning
45-70 1S 22" medium weight barrel with sites. newer checkering, no warning
45-70 1S 22" medium weight barrel with sites. Non prefix checkering, Liberty Marked
45-70 1S 22" medium weight barrel with sites. newer checkering, Liberty Marked
45-70 1H 24" Heavy weight barrel with sites. newer checkering, Liberty Marked
45-70 1S 22" medium weight barrel with sites. newer checkering, mottled pad, no warning (1977ish)
45-70 1S 22" medium weight barrel with sites. newer checkering, mottled pad, with warning (may not exist)
45-70 Lyman centennial Grade 1. Cased, high grade wood and engraving. 28" heavy "D" weight barrel
45-70 Lyman centennial Grade 2. Cased, stock wood and machine engraving. 28" heavy "D" weight barrel
45-70 Lyman centennial overrun. Stock wood and no engraving. 28" heavy "D" weight barrel
45-70 1S 50th anniversary gun. 22" medium weight barrel with sites. heavily engraved and Turkish walnut.
45-70 1S 22" medium weight barrel with sites. newer checkering, with warning
45-70 1S 22" medium weight barrel with sites. newer checkering, with warning Stainless
45-70 1S 22" medium weight barrel with sites. newer checkering, with warning. Cabela's edition Turnbull colors and finished. (not factory direct)
you also have 3 (I think) variations on the #3 in 45-70
good luck, and get the book!
Dave