Bingo Websites:
Here you will find links to Bingo games parts suppliers (including rails and backglasses)
www.bingo.cdyn.com
www.danny.cdyn.com

Also if you listen to podcasts, there is a new one that specialises in Bingo games.  They are short daily podcast that have being going for about one month. I got the links above from Episode 2:
www.foramusementonly.libsyn.com

Rail orientation:
The photo you have of the alternate machine is not what I would have expected.  I thought the rails were always 'flat' not 'tall'.  Have a look through the websites above - there is a good chance you will find your two machines.

History:
The person you bought from is not the owner from DOCs (the owners name is tony), but the machines were definitely stored at 70 Lygon St east Brunswick.  I'd like to believe in the nice story that they were obtain from the rear room of the former Cafe L'Amore two doors up.  (The name L'Amore now appears at the top of the front facade of the new building of Gelobar).
Oh well he was tall, but the dark skin is a southern trait. Near enough :).