Adding a Bonus film to a Blu-ray title

[Tns49]

I recently added a entry for Bucking Broadway, but cannot figure out how to add it to the Blu-ray entry for Stagecoach without screwing up the entry for Stagecoach.

Also brings up the fact that currently the date figures don't allow you to go back before 1880. Harry Carey was born in 1878. I am sure several other cast and crew were born earlier. Harry Carey starred in some movies even into the 30's and appeared in others until 1948. Bucking Broadway is 1917.