Antique diebold lock help

[IRONKICKER]

Good morning - i am also a newbie to your sight - have been reading hear for a few weeks and feel i am ready to try a post. Most of the time i can work w/ these locks until satisfied but having some problems on a old diebold lock - not sure if it is a peerless / eagle or what. For you pros you may feel this is a dumb question but here we go
1) what are the holes in the cover - through the discs and into the main housing for.
2) what is the brass plate for in the bottom of the housing as shown in the last photo
3) my drum that the discs turn on is in very poor condition - can it be replaced and does anyone have one?

Not sure if i posted this in the correnct place
thank you for the time and help invested in this sight ron