There are several orthodox mainline Daito-ryu videos. If you go to www.aikidojournal.com
you will find 2 DVD's on the instruction of the Ikkajo series of techniques and 2 excelent demonstration DVD's. Then if you go to www.budovideos.com
you will find 3 pages of Daito-ryu videos. I prefer the ones by Kondo sensei, they are very good and informative.
Of course in this site there are a lot of other ones to choose from.